Inline WebViewUpdater into WebViewUpdateServiceImpl.

Since the removal of the fallback logic and other complexity required by
Monochrome, WebViewUpdateServiceImpl did not have much logic left in it
other than forwarding most method calls to WebViewUpdater. The division
of logic between these two classes was thus mostly just making it harder
to understand.

Therefore, we inline the entirety of WebViewUpdater into
WebViewUpdateServiceImpl, combining them back into a single class as
they used to be when they were simpler. A number of methods are made
private as they don't need to be accessed from outside the class any
more.

Bug: 129470358
Test: atest WebViewUpdateServiceTest
Change-Id: I1cef1c89f47a3ddd980d0f7d27a09e9a1e1b913b

2 files changed, 555 insertions, 624 deletions

diff --git a/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java b/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
index 55697d39fb99..4d670f1eb59c 100644
--- a/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
+++ b/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
@@ -15,15 +15,22 @@
  */
 package com.android.server.webkit;
 
+import android.annotation.Nullable;
 import android.content.Context;
 import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.Signature;
 import android.os.AsyncTask;
 import android.os.UserHandle;
 import android.util.Slog;
+import android.webkit.UserPackage;
+import android.webkit.WebViewFactory;
 import android.webkit.WebViewProviderInfo;
 import android.webkit.WebViewProviderResponse;
 
 import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Implementation of the WebViewUpdateService.
@@ -33,10 +40,10 @@ import java.io.PrintWriter;
  * This class keeps track of and prepares the current WebView implementation, and needs to keep
  * track of a couple of different things such as what package is used as WebView implementation.
  *
- * The public methods in this class are accessed from WebViewUpdateService either on the UI thread
- * or on one of multiple Binder threads. The WebView preparation code shares state between threads
- * meaning that code that chooses a new WebView implementation or checks which implementation is
- * being used needs to hold a lock.
+ * The package-visible methods in this class are accessed from WebViewUpdateService either on the UI
+ * thread or on one of multiple Binder threads. The WebView preparation code shares state between
+ * threads meaning that code that chooses a new WebView implementation or checks which
+ * implementation is being used needs to hold a lock.
  *
  * The WebViewUpdateService can be accessed in a couple of different ways.
  * 1. It is started from the SystemServer at boot - at that point we just initiate some state such
@@ -55,36 +62,133 @@ import java.io.PrintWriter;
  *
  * @hide
  */
-public class WebViewUpdateServiceImpl {
+class WebViewUpdateServiceImpl {
     private static final String TAG = WebViewUpdateServiceImpl.class.getSimpleName();
 
-    private SystemInterface mSystemInterface;
-    private WebViewUpdater mWebViewUpdater;
-    final private Context mContext;
+    private static class WebViewPackageMissingException extends Exception {
+        WebViewPackageMissingException(String message) {
+            super(message);
+        }
+
+        WebViewPackageMissingException(Exception e) {
+            super(e);
+        }
+    }
+
+    private static final int WAIT_TIMEOUT_MS = 1000; // KEY_DISPATCHING_TIMEOUT is 5000.
+    private static final long NS_PER_MS = 1000000;
+
+    private static final int VALIDITY_OK = 0;
+    private static final int VALIDITY_INCORRECT_SDK_VERSION = 1;
+    private static final int VALIDITY_INCORRECT_VERSION_CODE = 2;
+    private static final int VALIDITY_INCORRECT_SIGNATURE = 3;
+    private static final int VALIDITY_NO_LIBRARY_FLAG = 4;
+
+    private static final int MULTIPROCESS_SETTING_ON_VALUE = Integer.MAX_VALUE;
+    private static final int MULTIPROCESS_SETTING_OFF_VALUE = Integer.MIN_VALUE;
+
+    private final SystemInterface mSystemInterface;
+    private final Context mContext;
 
-    private final static int MULTIPROCESS_SETTING_ON_VALUE = Integer.MAX_VALUE;
-    private final static int MULTIPROCESS_SETTING_OFF_VALUE = Integer.MIN_VALUE;
+    private long mMinimumVersionCode = -1;
 
-    public WebViewUpdateServiceImpl(Context context, SystemInterface systemInterface) {
+    // Keeps track of the number of running relro creations
+    private int mNumRelroCreationsStarted = 0;
+    private int mNumRelroCreationsFinished = 0;
+    // Implies that we need to rerun relro creation because we are using an out-of-date package
+    private boolean mWebViewPackageDirty = false;
+    private boolean mAnyWebViewInstalled = false;
+
+    private static final int NUMBER_OF_RELROS_UNKNOWN = Integer.MAX_VALUE;
+
+    // The WebView package currently in use (or the one we are preparing).
+    private PackageInfo mCurrentWebViewPackage = null;
+
+    private final Object mLock = new Object();
+
+    WebViewUpdateServiceImpl(Context context, SystemInterface systemInterface) {
         mContext = context;
         mSystemInterface = systemInterface;
-        mWebViewUpdater = new WebViewUpdater(mContext, mSystemInterface);
     }
 
     void packageStateChanged(String packageName, int changedState, int userId) {
         // We don't early out here in different cases where we could potentially early-out (e.g. if
         // we receive PACKAGE_CHANGED for another user than the system user) since that would
         // complicate this logic further and open up for more edge cases.
-        mWebViewUpdater.packageStateChanged(packageName, changedState);
+        for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) {
+            String webviewPackage = provider.packageName;
+
+            if (webviewPackage.equals(packageName)) {
+                boolean updateWebView = false;
+                boolean removedOrChangedOldPackage = false;
+                String oldProviderName = null;
+                PackageInfo newPackage = null;
+                synchronized (mLock) {
+                    try {
+                        newPackage = findPreferredWebViewPackage();
+                        if (mCurrentWebViewPackage != null) {
+                            oldProviderName = mCurrentWebViewPackage.packageName;
+                        }
+                        // Only trigger update actions if the updated package is the one
+                        // that will be used, or the one that was in use before the
+                        // update, or if we haven't seen a valid WebView package before.
+                        updateWebView =
+                            provider.packageName.equals(newPackage.packageName)
+                            || provider.packageName.equals(oldProviderName)
+                            || mCurrentWebViewPackage == null;
+                        // We removed the old package if we received an intent to remove
+                        // or replace the old package.
+                        removedOrChangedOldPackage =
+                            provider.packageName.equals(oldProviderName);
+                        if (updateWebView) {
+                            onWebViewProviderChanged(newPackage);
+                        }
+                    } catch (WebViewPackageMissingException e) {
+                        mCurrentWebViewPackage = null;
+                        Slog.e(TAG, "Could not find valid WebView package to create relro with "
+                                + e);
+                    }
+                }
+                if (updateWebView && !removedOrChangedOldPackage
+                        && oldProviderName != null) {
+                    // If the provider change is the result of adding or replacing a
+                    // package that was not the previous provider then we must kill
+                    // packages dependent on the old package ourselves. The framework
+                    // only kills dependents of packages that are being removed.
+                    mSystemInterface.killPackageDependents(oldProviderName);
+                }
+                return;
+            }
+        }
     }
 
     void prepareWebViewInSystemServer() {
-        mWebViewUpdater.prepareWebViewInSystemServer();
+        try {
+            synchronized (mLock) {
+                mCurrentWebViewPackage = findPreferredWebViewPackage();
+                String userSetting = mSystemInterface.getUserChosenWebViewProvider(mContext);
+                if (userSetting != null
+                        && !userSetting.equals(mCurrentWebViewPackage.packageName)) {
+                    // Don't persist the user-chosen setting across boots if the package being
+                    // chosen is not used (could be disabled or uninstalled) so that the user won't
+                    // be surprised by the device switching to using a certain webview package,
+                    // that was uninstalled/disabled a long time ago, if it is installed/enabled
+                    // again.
+                    mSystemInterface.updateUserSetting(mContext,
+                            mCurrentWebViewPackage.packageName);
+                }
+                onWebViewProviderChanged(mCurrentWebViewPackage);
+            }
+        } catch (Throwable t) {
+            // Log and discard errors at this stage as we must not crash the system server.
+            Slog.e(TAG, "error preparing webview provider from system server", t);
+        }
+
         if (getCurrentWebViewPackage() == null) {
             // We didn't find a valid WebView implementation. Try explicitly re-enabling the
             // fallback package for all users in case it was disabled, even if we already did the
-            // one-time migration before. If this actually changes the state, WebViewUpdater will
-            // see the PackageManager broadcast shortly and try again.
+            // one-time migration before. If this actually changes the state, we will see the
+            // PackageManager broadcast shortly and try again.
             WebViewProviderInfo[] webviewProviders = mSystemInterface.getWebViewPackages();
             WebViewProviderInfo fallbackProvider = getFallbackProvider(webviewProviders);
             if (fallbackProvider != null) {
@@ -103,7 +207,7 @@ public class WebViewUpdateServiceImpl {
         }
     }
 
-    void startZygoteWhenReady() {
+    private void startZygoteWhenReady() {
         // Wait on a background thread for RELRO creation to be done. We ignore the return value
         // because even if RELRO creation failed we still want to start the zygote.
         waitForAndGetProvider();
@@ -129,23 +233,231 @@ public class WebViewUpdateServiceImpl {
      */
     private void handleUserChange() {
         // Potentially trigger package-changing logic.
-        mWebViewUpdater.updateCurrentWebViewPackage(null);
+        updateCurrentWebViewPackage(null);
     }
 
     void notifyRelroCreationCompleted() {
-        mWebViewUpdater.notifyRelroCreationCompleted();
+        synchronized (mLock) {
+            mNumRelroCreationsFinished++;
+            checkIfRelrosDoneLocked();
+        }
     }
 
     WebViewProviderResponse waitForAndGetProvider() {
-        return mWebViewUpdater.waitForAndGetProvider();
+        PackageInfo webViewPackage = null;
+        final long timeoutTimeMs = System.nanoTime() / NS_PER_MS + WAIT_TIMEOUT_MS;
+        boolean webViewReady = false;
+        int webViewStatus = WebViewFactory.LIBLOAD_SUCCESS;
+        synchronized (mLock) {
+            webViewReady = webViewIsReadyLocked();
+            while (!webViewReady) {
+                final long timeNowMs = System.nanoTime() / NS_PER_MS;
+                if (timeNowMs >= timeoutTimeMs) break;
+                try {
+                    mLock.wait(timeoutTimeMs - timeNowMs);
+                } catch (InterruptedException e) {
+                    // ignore
+                }
+                webViewReady = webViewIsReadyLocked();
+            }
+            // Make sure we return the provider that was used to create the relro file
+            webViewPackage = mCurrentWebViewPackage;
+            if (webViewReady) {
+                // success
+            } else if (!mAnyWebViewInstalled) {
+                webViewStatus = WebViewFactory.LIBLOAD_FAILED_LISTING_WEBVIEW_PACKAGES;
+            } else {
+                // Either the current relro creation  isn't done yet, or the new relro creatioin
+                // hasn't kicked off yet (the last relro creation used an out-of-date WebView).
+                webViewStatus = WebViewFactory.LIBLOAD_FAILED_WAITING_FOR_RELRO;
+                Slog.e(TAG, "Timed out waiting for relro creation, relros started "
+                        + mNumRelroCreationsStarted
+                        + " relros finished " + mNumRelroCreationsFinished
+                        + " package dirty? " + mWebViewPackageDirty);
+            }
+        }
+        if (!webViewReady) Slog.w(TAG, "creating relro file timed out");
+        return new WebViewProviderResponse(webViewPackage, webViewStatus);
     }
 
-    String changeProviderAndSetting(String newProvider) {
-        return mWebViewUpdater.changeProviderAndSetting(newProvider);
+    /**
+     * Change WebView provider and provider setting and kill packages using the old provider.
+     * Return the new provider (in case we are in the middle of creating relro files, or
+     * replacing that provider it will not be in use directly, but will be used when the relros
+     * or the replacement are done).
+     */
+    String changeProviderAndSetting(String newProviderName) {
+        PackageInfo newPackage = updateCurrentWebViewPackage(newProviderName);
+        if (newPackage == null) return "";
+        return newPackage.packageName;
     }
 
+    /**
+     * Update the current WebView package.
+     * @param newProviderName the package to switch to, null if no package has been explicitly
+     * chosen.
+     */
+    private PackageInfo updateCurrentWebViewPackage(@Nullable String newProviderName) {
+        PackageInfo oldPackage = null;
+        PackageInfo newPackage = null;
+        boolean providerChanged = false;
+        synchronized (mLock) {
+            oldPackage = mCurrentWebViewPackage;
+
+            if (newProviderName != null) {
+                mSystemInterface.updateUserSetting(mContext, newProviderName);
+            }
+
+            try {
+                newPackage = findPreferredWebViewPackage();
+                providerChanged = (oldPackage == null)
+                        || !newPackage.packageName.equals(oldPackage.packageName);
+            } catch (WebViewPackageMissingException e) {
+                // If updated the Setting but don't have an installed WebView package, the
+                // Setting will be used when a package is available.
+                mCurrentWebViewPackage = null;
+                Slog.e(TAG, "Couldn't find WebView package to use " + e);
+                return null;
+            }
+            // Perform the provider change if we chose a new provider
+            if (providerChanged) {
+                onWebViewProviderChanged(newPackage);
+            }
+        }
+        // Kill apps using the old provider only if we changed provider
+        if (providerChanged && oldPackage != null) {
+            mSystemInterface.killPackageDependents(oldPackage.packageName);
+        }
+        // Return the new provider, this is not necessarily the one we were asked to switch to,
+        // but the persistent setting will now be pointing to the provider we were asked to
+        // switch to anyway.
+        return newPackage;
+    }
+
+    /**
+     * This is called when we change WebView provider, either when the current provider is
+     * updated or a new provider is chosen / takes precedence.
+     */
+    private void onWebViewProviderChanged(PackageInfo newPackage) {
+        synchronized (mLock) {
+            mAnyWebViewInstalled = true;
+            if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) {
+                mCurrentWebViewPackage = newPackage;
+
+                // The relro creations might 'finish' (not start at all) before
+                // WebViewFactory.onWebViewProviderChanged which means we might not know the
+                // number of started creations before they finish.
+                mNumRelroCreationsStarted = NUMBER_OF_RELROS_UNKNOWN;
+                mNumRelroCreationsFinished = 0;
+                mNumRelroCreationsStarted =
+                    mSystemInterface.onWebViewProviderChanged(newPackage);
+                // If the relro creations finish before we know the number of started creations
+                // we will have to do any cleanup/notifying here.
+                checkIfRelrosDoneLocked();
+            } else {
+                mWebViewPackageDirty = true;
+            }
+        }
+    }
+
+    /**
+     * Fetch only the currently valid WebView packages.
+     **/
     WebViewProviderInfo[] getValidWebViewPackages() {
-        return mWebViewUpdater.getValidWebViewPackages();
+        ProviderAndPackageInfo[] providersAndPackageInfos = getValidWebViewPackagesAndInfos();
+        WebViewProviderInfo[] providers =
+            new WebViewProviderInfo[providersAndPackageInfos.length];
+        for (int n = 0; n < providersAndPackageInfos.length; n++) {
+            providers[n] = providersAndPackageInfos[n].provider;
+        }
+        return providers;
+    }
+
+    private static class ProviderAndPackageInfo {
+        public final WebViewProviderInfo provider;
+        public final PackageInfo packageInfo;
+
+        ProviderAndPackageInfo(WebViewProviderInfo provider, PackageInfo packageInfo) {
+            this.provider = provider;
+            this.packageInfo = packageInfo;
+        }
+    }
+
+    private ProviderAndPackageInfo[] getValidWebViewPackagesAndInfos() {
+        WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages();
+        List<ProviderAndPackageInfo> providers = new ArrayList<>();
+        for (int n = 0; n < allProviders.length; n++) {
+            try {
+                PackageInfo packageInfo =
+                        mSystemInterface.getPackageInfoForProvider(allProviders[n]);
+                if (validityResult(allProviders[n], packageInfo) == VALIDITY_OK) {
+                    providers.add(new ProviderAndPackageInfo(allProviders[n], packageInfo));
+                }
+            } catch (NameNotFoundException e) {
+                // Don't add non-existent packages
+            }
+        }
+        return providers.toArray(new ProviderAndPackageInfo[providers.size()]);
+    }
+
+    /**
+     * Returns either the package info of the WebView provider determined in the following way:
+     * If the user has chosen a provider then use that if it is valid,
+     * otherwise use the first package in the webview priority list that is valid.
+     *
+     */
+    private PackageInfo findPreferredWebViewPackage() throws WebViewPackageMissingException {
+        ProviderAndPackageInfo[] providers = getValidWebViewPackagesAndInfos();
+
+        String userChosenProvider = mSystemInterface.getUserChosenWebViewProvider(mContext);
+
+        // If the user has chosen provider, use that (if it's installed and enabled for all
+        // users).
+        for (ProviderAndPackageInfo providerAndPackage : providers) {
+            if (providerAndPackage.provider.packageName.equals(userChosenProvider)) {
+                // userPackages can contain null objects.
+                List<UserPackage> userPackages =
+                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
+                                providerAndPackage.provider);
+                if (isInstalledAndEnabledForAllUsers(userPackages)) {
+                    return providerAndPackage.packageInfo;
+                }
+            }
+        }
+
+        // User did not choose, or the choice failed; use the most stable provider that is
+        // installed and enabled for all users, and available by default (not through
+        // user choice).
+        for (ProviderAndPackageInfo providerAndPackage : providers) {
+            if (providerAndPackage.provider.availableByDefault) {
+                // userPackages can contain null objects.
+                List<UserPackage> userPackages =
+                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
+                                providerAndPackage.provider);
+                if (isInstalledAndEnabledForAllUsers(userPackages)) {
+                    return providerAndPackage.packageInfo;
+                }
+            }
+        }
+
+        // This should never happen during normal operation (only with modified system images).
+        mAnyWebViewInstalled = false;
+        throw new WebViewPackageMissingException("Could not find a loadable WebView package");
+    }
+
+    /**
+     * Return true iff {@param packageInfos} point to only installed and enabled packages.
+     * The given packages {@param packageInfos} should all be pointing to the same package, but each
+     * PackageInfo representing a different user's package.
+     */
+    private static boolean isInstalledAndEnabledForAllUsers(
+            List<UserPackage> userPackages) {
+        for (UserPackage userPackage : userPackages) {
+            if (!userPackage.isInstalledPackage() || !userPackage.isEnabledPackage()) {
+                return false;
+            }
+        }
+        return true;
     }
 
     WebViewProviderInfo[] getWebViewPackages() {
@@ -153,7 +465,143 @@ public class WebViewUpdateServiceImpl {
     }
 
     PackageInfo getCurrentWebViewPackage() {
-        return mWebViewUpdater.getCurrentWebViewPackage();
+        synchronized (mLock) {
+            return mCurrentWebViewPackage;
+        }
+    }
+
+    /**
+     * Returns whether WebView is ready and is not going to go through its preparation phase
+     * again directly.
+     */
+    private boolean webViewIsReadyLocked() {
+        return !mWebViewPackageDirty
+            && (mNumRelroCreationsStarted == mNumRelroCreationsFinished)
+            // The current package might be replaced though we haven't received an intent
+            // declaring this yet, the following flag makes anyone loading WebView to wait in
+            // this case.
+            && mAnyWebViewInstalled;
+    }
+
+    private void checkIfRelrosDoneLocked() {
+        if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) {
+            if (mWebViewPackageDirty) {
+                mWebViewPackageDirty = false;
+                // If we have changed provider since we started the relro creation we need to
+                // redo the whole process using the new package instead.
+                try {
+                    PackageInfo newPackage = findPreferredWebViewPackage();
+                    onWebViewProviderChanged(newPackage);
+                } catch (WebViewPackageMissingException e) {
+                    mCurrentWebViewPackage = null;
+                    // If we can't find any valid WebView package we are now in a state where
+                    // mAnyWebViewInstalled is false, so loading WebView will be blocked and we
+                    // should simply wait until we receive an intent declaring a new package was
+                    // installed.
+                }
+            } else {
+                mLock.notifyAll();
+            }
+        }
+    }
+
+    private int validityResult(WebViewProviderInfo configInfo, PackageInfo packageInfo) {
+        // Ensure the provider targets this framework release (or a later one).
+        if (!UserPackage.hasCorrectTargetSdkVersion(packageInfo)) {
+            return VALIDITY_INCORRECT_SDK_VERSION;
+        }
+        if (!versionCodeGE(packageInfo.getLongVersionCode(), getMinimumVersionCode())
+                && !mSystemInterface.systemIsDebuggable()) {
+            // Webview providers may be downgraded arbitrarily low, prevent that by enforcing
+            // minimum version code. This check is only enforced for user builds.
+            return VALIDITY_INCORRECT_VERSION_CODE;
+        }
+        if (!providerHasValidSignature(configInfo, packageInfo, mSystemInterface)) {
+            return VALIDITY_INCORRECT_SIGNATURE;
+        }
+        if (WebViewFactory.getWebViewLibrary(packageInfo.applicationInfo) == null) {
+            return VALIDITY_NO_LIBRARY_FLAG;
+        }
+        return VALIDITY_OK;
+    }
+
+    /**
+     * Both versionCodes should be from a WebView provider package implemented by Chromium.
+     * VersionCodes from other kinds of packages won't make any sense in this method.
+     *
+     * An introduction to Chromium versionCode scheme:
+     * "BBBBPPPXX"
+     * BBBB: 4 digit branch number. It monotonically increases over time.
+     * PPP: patch number in the branch. It is padded with zeroes to the left. These three digits
+     * may change their meaning in the future.
+     * XX: Digits to differentiate different APK builds of the same source version.
+     *
+     * This method takes the "BBBB" of versionCodes and compare them.
+     *
+     * https://www.chromium.org/developers/version-numbers describes general Chromium versioning;
+     * https://source.chromium.org/chromium/chromium/src/+/master:build/util/android_chrome_version.py
+     * is the canonical source for how Chromium versionCodes are calculated.
+     *
+     * @return true if versionCode1 is higher than or equal to versionCode2.
+     */
+    private static boolean versionCodeGE(long versionCode1, long versionCode2) {
+        long v1 = versionCode1 / 100000;
+        long v2 = versionCode2 / 100000;
+
+        return v1 >= v2;
+    }
+
+    /**
+     * Gets the minimum version code allowed for a valid provider. It is the minimum versionCode
+     * of all available-by-default WebView provider packages. If there is no such WebView provider
+     * package on the system, then return -1, which means all positive versionCode WebView packages
+     * are accepted.
+     *
+     * Note that this is a private method that handles a variable (mMinimumVersionCode) which is
+     * shared between threads. Furthermore, this method does not hold mLock meaning that we must
+     * take extra care to ensure this method is thread-safe.
+     */
+    private long getMinimumVersionCode() {
+        if (mMinimumVersionCode > 0) {
+            return mMinimumVersionCode;
+        }
+
+        long minimumVersionCode = -1;
+        for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) {
+            if (provider.availableByDefault) {
+                try {
+                    long versionCode =
+                            mSystemInterface.getFactoryPackageVersion(provider.packageName);
+                    if (minimumVersionCode < 0 || versionCode < minimumVersionCode) {
+                        minimumVersionCode = versionCode;
+                    }
+                } catch (NameNotFoundException e) {
+                    // Safe to ignore.
+                }
+            }
+        }
+
+        mMinimumVersionCode = minimumVersionCode;
+        return mMinimumVersionCode;
+    }
+
+    private static boolean providerHasValidSignature(WebViewProviderInfo provider,
+            PackageInfo packageInfo, SystemInterface systemInterface) {
+        // Skip checking signatures on debuggable builds, for development purposes.
+        if (systemInterface.systemIsDebuggable()) return true;
+
+        // Allow system apps to be valid providers regardless of signature.
+        if (packageInfo.applicationInfo.isSystemApp()) return true;
+
+        // We don't support packages with multiple signatures.
+        if (packageInfo.signatures.length != 1) return false;
+
+        // If any of the declared signatures match the package signature, it's valid.
+        for (Signature signature : provider.signatures) {
+            if (signature.equals(packageInfo.signatures[0])) return true;
+        }
+
+        return false;
     }
 
     /**
@@ -195,6 +643,88 @@ public class WebViewUpdateServiceImpl {
     void dumpState(PrintWriter pw) {
         pw.println("Current WebView Update Service state");
         pw.println(String.format("  Multiprocess enabled: %b", isMultiProcessEnabled()));
-        mWebViewUpdater.dumpState(pw);
+        synchronized (mLock) {
+            if (mCurrentWebViewPackage == null) {
+                pw.println("  Current WebView package is null");
+            } else {
+                pw.println(String.format("  Current WebView package (name, version): (%s, %s)",
+                        mCurrentWebViewPackage.packageName,
+                        mCurrentWebViewPackage.versionName));
+            }
+            pw.println(String.format("  Minimum targetSdkVersion: %d",
+                    UserPackage.MINIMUM_SUPPORTED_SDK));
+            pw.println(String.format("  Minimum WebView version code: %d",
+                    mMinimumVersionCode));
+            pw.println(String.format("  Number of relros started: %d",
+                    mNumRelroCreationsStarted));
+            pw.println(String.format("  Number of relros finished: %d",
+                        mNumRelroCreationsFinished));
+            pw.println(String.format("  WebView package dirty: %b", mWebViewPackageDirty));
+            pw.println(String.format("  Any WebView package installed: %b",
+                    mAnyWebViewInstalled));
+
+            try {
+                PackageInfo preferredWebViewPackage = findPreferredWebViewPackage();
+                pw.println(String.format(
+                        "  Preferred WebView package (name, version): (%s, %s)",
+                        preferredWebViewPackage.packageName,
+                        preferredWebViewPackage.versionName));
+            } catch (WebViewPackageMissingException e) {
+                pw.println(String.format("  Preferred WebView package: none"));
+            }
+
+            dumpAllPackageInformationLocked(pw);
+        }
+    }
+
+    private void dumpAllPackageInformationLocked(PrintWriter pw) {
+        WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages();
+        pw.println("  WebView packages:");
+        for (WebViewProviderInfo provider : allProviders) {
+            List<UserPackage> userPackages =
+                    mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider);
+            PackageInfo systemUserPackageInfo =
+                    userPackages.get(UserHandle.USER_SYSTEM).getPackageInfo();
+            if (systemUserPackageInfo == null) {
+                pw.println(String.format("    %s is NOT installed.", provider.packageName));
+                continue;
+            }
+
+            int validity = validityResult(provider, systemUserPackageInfo);
+            String packageDetails = String.format(
+                    "versionName: %s, versionCode: %d, targetSdkVersion: %d",
+                    systemUserPackageInfo.versionName,
+                    systemUserPackageInfo.getLongVersionCode(),
+                    systemUserPackageInfo.applicationInfo.targetSdkVersion);
+            if (validity == VALIDITY_OK) {
+                boolean installedForAllUsers = isInstalledAndEnabledForAllUsers(
+                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider));
+                pw.println(String.format(
+                        "    Valid package %s (%s) is %s installed/enabled for all users",
+                        systemUserPackageInfo.packageName,
+                        packageDetails,
+                        installedForAllUsers ? "" : "NOT"));
+            } else {
+                pw.println(String.format("    Invalid package %s (%s), reason: %s",
+                        systemUserPackageInfo.packageName,
+                        packageDetails,
+                        getInvalidityReason(validity)));
+            }
+        }
+    }
+
+    private static String getInvalidityReason(int invalidityReason) {
+        switch (invalidityReason) {
+            case VALIDITY_INCORRECT_SDK_VERSION:
+                return "SDK version too low";
+            case VALIDITY_INCORRECT_VERSION_CODE:
+                return "Version code too low";
+            case VALIDITY_INCORRECT_SIGNATURE:
+                return "Incorrect signature";
+            case VALIDITY_NO_LIBRARY_FLAG:
+                return "No WebView-library manifest flag";
+            default:
+                return "Unexcepted validity-reason";
+        }
     }
 }
diff --git a/services/core/java/com/android/server/webkit/WebViewUpdater.java b/services/core/java/com/android/server/webkit/WebViewUpdater.java
deleted file mode 100644
index 3b58af2a200f..000000000000
--- a/services/core/java/com/android/server/webkit/WebViewUpdater.java
+++ /dev/null
@@ -1,599 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.android.server.webkit;
-
-import android.content.Context;
-import android.content.pm.PackageInfo;
-import android.content.pm.PackageManager.NameNotFoundException;
-import android.content.pm.Signature;
-import android.os.UserHandle;
-import android.util.Slog;
-import android.webkit.UserPackage;
-import android.webkit.WebViewFactory;
-import android.webkit.WebViewProviderInfo;
-import android.webkit.WebViewProviderResponse;
-
-import java.io.PrintWriter;
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Class that decides what WebView implementation to use and prepares that implementation for
- * use.
- */
-class WebViewUpdater {
-    private static final String TAG = WebViewUpdater.class.getSimpleName();
-
-    private static class WebViewPackageMissingException extends Exception {
-        public WebViewPackageMissingException(String message) { super(message); }
-        public WebViewPackageMissingException(Exception e) { super(e); }
-    }
-
-    private static final int WAIT_TIMEOUT_MS = 1000; // KEY_DISPATCHING_TIMEOUT is 5000.
-
-    private final static int VALIDITY_OK = 0;
-    private final static int VALIDITY_INCORRECT_SDK_VERSION = 1;
-    private final static int VALIDITY_INCORRECT_VERSION_CODE = 2;
-    private final static int VALIDITY_INCORRECT_SIGNATURE = 3;
-    private final static int VALIDITY_NO_LIBRARY_FLAG = 4;
-
-    private Context mContext;
-    private SystemInterface mSystemInterface;
-    private long mMinimumVersionCode = -1;
-
-    // Keeps track of the number of running relro creations
-    private int mNumRelroCreationsStarted = 0;
-    private int mNumRelroCreationsFinished = 0;
-    // Implies that we need to rerun relro creation because we are using an out-of-date package
-    private boolean mWebViewPackageDirty = false;
-    private boolean mAnyWebViewInstalled = false;
-
-    private int NUMBER_OF_RELROS_UNKNOWN = Integer.MAX_VALUE;
-
-    // The WebView package currently in use (or the one we are preparing).
-    private PackageInfo mCurrentWebViewPackage = null;
-
-    private final Object mLock = new Object();
-
-    WebViewUpdater(Context context, SystemInterface systemInterface) {
-        mContext = context;
-        mSystemInterface = systemInterface;
-    }
-
-    void packageStateChanged(String packageName, int changedState) {
-        for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) {
-            String webviewPackage = provider.packageName;
-
-            if (webviewPackage.equals(packageName)) {
-                boolean updateWebView = false;
-                boolean removedOrChangedOldPackage = false;
-                String oldProviderName = null;
-                PackageInfo newPackage = null;
-                synchronized(mLock) {
-                    try {
-                        newPackage = findPreferredWebViewPackage();
-                        if (mCurrentWebViewPackage != null) {
-                            oldProviderName = mCurrentWebViewPackage.packageName;
-                        }
-                        // Only trigger update actions if the updated package is the one
-                        // that will be used, or the one that was in use before the
-                        // update, or if we haven't seen a valid WebView package before.
-                        updateWebView =
-                            provider.packageName.equals(newPackage.packageName)
-                            || provider.packageName.equals(oldProviderName)
-                            || mCurrentWebViewPackage == null;
-                        // We removed the old package if we received an intent to remove
-                        // or replace the old package.
-                        removedOrChangedOldPackage =
-                            provider.packageName.equals(oldProviderName);
-                        if (updateWebView) {
-                            onWebViewProviderChanged(newPackage);
-                        }
-                    } catch (WebViewPackageMissingException e) {
-                        mCurrentWebViewPackage = null;
-                        Slog.e(TAG, "Could not find valid WebView package to create " +
-                                "relro with " + e);
-                    }
-                }
-                if(updateWebView && !removedOrChangedOldPackage
-                        && oldProviderName != null) {
-                    // If the provider change is the result of adding or replacing a
-                    // package that was not the previous provider then we must kill
-                    // packages dependent on the old package ourselves. The framework
-                    // only kills dependents of packages that are being removed.
-                    mSystemInterface.killPackageDependents(oldProviderName);
-                }
-                return;
-            }
-        }
-    }
-
-    void prepareWebViewInSystemServer() {
-        try {
-            synchronized(mLock) {
-                mCurrentWebViewPackage = findPreferredWebViewPackage();
-                String userSetting = mSystemInterface.getUserChosenWebViewProvider(mContext);
-                if (userSetting != null
-                        && !userSetting.equals(mCurrentWebViewPackage.packageName)) {
-                    // Don't persist the user-chosen setting across boots if the package being
-                    // chosen is not used (could be disabled or uninstalled) so that the user won't
-                    // be surprised by the device switching to using a certain webview package,
-                    // that was uninstalled/disabled a long time ago, if it is installed/enabled
-                    // again.
-                    mSystemInterface.updateUserSetting(mContext,
-                            mCurrentWebViewPackage.packageName);
-                }
-                onWebViewProviderChanged(mCurrentWebViewPackage);
-            }
-        } catch (Throwable t) {
-            // Log and discard errors at this stage as we must not crash the system server.
-            Slog.e(TAG, "error preparing webview provider from system server", t);
-        }
-    }
-
-    /**
-     * Change WebView provider and provider setting and kill packages using the old provider.
-     * Return the new provider (in case we are in the middle of creating relro files, or
-     * replacing that provider it will not be in use directly, but will be used when the relros
-     * or the replacement are done).
-     */
-    String changeProviderAndSetting(String newProviderName) {
-        PackageInfo newPackage = updateCurrentWebViewPackage(newProviderName);
-        if (newPackage == null) return "";
-        return newPackage.packageName;
-    }
-
-    /**
-     * Update the current WebView package.
-     * @param newProviderName the package to switch to, null if no package has been explicitly
-     * chosen.
-     */
-    PackageInfo updateCurrentWebViewPackage(String newProviderName) {
-        PackageInfo oldPackage = null;
-        PackageInfo newPackage = null;
-        boolean providerChanged = false;
-        synchronized(mLock) {
-            oldPackage = mCurrentWebViewPackage;
-
-            if (newProviderName != null) {
-                mSystemInterface.updateUserSetting(mContext, newProviderName);
-            }
-
-            try {
-                newPackage = findPreferredWebViewPackage();
-                providerChanged = (oldPackage == null)
-                        || !newPackage.packageName.equals(oldPackage.packageName);
-            } catch (WebViewPackageMissingException e) {
-                // If updated the Setting but don't have an installed WebView package, the
-                // Setting will be used when a package is available.
-                mCurrentWebViewPackage = null;
-                Slog.e(TAG, "Couldn't find WebView package to use " + e);
-                return null;
-            }
-            // Perform the provider change if we chose a new provider
-            if (providerChanged) {
-                onWebViewProviderChanged(newPackage);
-            }
-        }
-        // Kill apps using the old provider only if we changed provider
-        if (providerChanged && oldPackage != null) {
-            mSystemInterface.killPackageDependents(oldPackage.packageName);
-        }
-        // Return the new provider, this is not necessarily the one we were asked to switch to,
-        // but the persistent setting will now be pointing to the provider we were asked to
-        // switch to anyway.
-        return newPackage;
-    }
-
-    /**
-     * This is called when we change WebView provider, either when the current provider is
-     * updated or a new provider is chosen / takes precedence.
-     */
-    private void onWebViewProviderChanged(PackageInfo newPackage) {
-        synchronized(mLock) {
-            mAnyWebViewInstalled = true;
-            if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) {
-                mCurrentWebViewPackage = newPackage;
-
-                // The relro creations might 'finish' (not start at all) before
-                // WebViewFactory.onWebViewProviderChanged which means we might not know the
-                // number of started creations before they finish.
-                mNumRelroCreationsStarted = NUMBER_OF_RELROS_UNKNOWN;
-                mNumRelroCreationsFinished = 0;
-                mNumRelroCreationsStarted =
-                    mSystemInterface.onWebViewProviderChanged(newPackage);
-                // If the relro creations finish before we know the number of started creations
-                // we will have to do any cleanup/notifying here.
-                checkIfRelrosDoneLocked();
-            } else {
-                mWebViewPackageDirty = true;
-            }
-        }
-    }
-
-    /**
-     * Fetch only the currently valid WebView packages.
-     **/
-    WebViewProviderInfo[] getValidWebViewPackages() {
-        ProviderAndPackageInfo[] providersAndPackageInfos = getValidWebViewPackagesAndInfos();
-        WebViewProviderInfo[] providers =
-            new WebViewProviderInfo[providersAndPackageInfos.length];
-        for(int n = 0; n < providersAndPackageInfos.length; n++) {
-            providers[n] = providersAndPackageInfos[n].provider;
-        }
-        return providers;
-    }
-
-    private static class ProviderAndPackageInfo {
-        public final WebViewProviderInfo provider;
-        public final PackageInfo packageInfo;
-
-        public ProviderAndPackageInfo(WebViewProviderInfo provider, PackageInfo packageInfo) {
-            this.provider = provider;
-            this.packageInfo = packageInfo;
-        }
-    }
-
-    private ProviderAndPackageInfo[] getValidWebViewPackagesAndInfos() {
-        WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages();
-        List<ProviderAndPackageInfo> providers = new ArrayList<>();
-        for(int n = 0; n < allProviders.length; n++) {
-            try {
-                PackageInfo packageInfo =
-                    mSystemInterface.getPackageInfoForProvider(allProviders[n]);
-                if (isValidProvider(allProviders[n], packageInfo)) {
-                    providers.add(new ProviderAndPackageInfo(allProviders[n], packageInfo));
-                }
-            } catch (NameNotFoundException e) {
-                // Don't add non-existent packages
-            }
-        }
-        return providers.toArray(new ProviderAndPackageInfo[providers.size()]);
-    }
-
-    /**
-     * Returns either the package info of the WebView provider determined in the following way:
-     * If the user has chosen a provider then use that if it is valid,
-     * otherwise use the first package in the webview priority list that is valid.
-     *
-     */
-    private PackageInfo findPreferredWebViewPackage() throws WebViewPackageMissingException {
-        ProviderAndPackageInfo[] providers = getValidWebViewPackagesAndInfos();
-
-        String userChosenProvider = mSystemInterface.getUserChosenWebViewProvider(mContext);
-
-        // If the user has chosen provider, use that (if it's installed and enabled for all
-        // users).
-        for (ProviderAndPackageInfo providerAndPackage : providers) {
-            if (providerAndPackage.provider.packageName.equals(userChosenProvider)) {
-                // userPackages can contain null objects.
-                List<UserPackage> userPackages =
-                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
-                                providerAndPackage.provider);
-                if (isInstalledAndEnabledForAllUsers(userPackages)) {
-                    return providerAndPackage.packageInfo;
-                }
-            }
-        }
-
-        // User did not choose, or the choice failed; use the most stable provider that is
-        // installed and enabled for all users, and available by default (not through
-        // user choice).
-        for (ProviderAndPackageInfo providerAndPackage : providers) {
-            if (providerAndPackage.provider.availableByDefault) {
-                // userPackages can contain null objects.
-                List<UserPackage> userPackages =
-                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext,
-                                providerAndPackage.provider);
-                if (isInstalledAndEnabledForAllUsers(userPackages)) {
-                    return providerAndPackage.packageInfo;
-                }
-            }
-        }
-
-        // This should never happen during normal operation (only with modified system images).
-        mAnyWebViewInstalled = false;
-        throw new WebViewPackageMissingException("Could not find a loadable WebView package");
-    }
-
-    /**
-     * Return true iff {@param packageInfos} point to only installed and enabled packages.
-     * The given packages {@param packageInfos} should all be pointing to the same package, but each
-     * PackageInfo representing a different user's package.
-     */
-    static boolean isInstalledAndEnabledForAllUsers(
-            List<UserPackage> userPackages) {
-        for (UserPackage userPackage : userPackages) {
-            if (!userPackage.isInstalledPackage() || !userPackage.isEnabledPackage()) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    void notifyRelroCreationCompleted() {
-        synchronized (mLock) {
-            mNumRelroCreationsFinished++;
-            checkIfRelrosDoneLocked();
-        }
-    }
-
-    WebViewProviderResponse waitForAndGetProvider() {
-        PackageInfo webViewPackage = null;
-        final long NS_PER_MS = 1000000;
-        final long timeoutTimeMs = System.nanoTime() / NS_PER_MS + WAIT_TIMEOUT_MS;
-        boolean webViewReady = false;
-        int webViewStatus = WebViewFactory.LIBLOAD_SUCCESS;
-        synchronized (mLock) {
-            webViewReady = webViewIsReadyLocked();
-            while (!webViewReady) {
-                final long timeNowMs = System.nanoTime() / NS_PER_MS;
-                if (timeNowMs >= timeoutTimeMs) break;
-                try {
-                    mLock.wait(timeoutTimeMs - timeNowMs);
-                } catch (InterruptedException e) {}
-                webViewReady = webViewIsReadyLocked();
-            }
-            // Make sure we return the provider that was used to create the relro file
-            webViewPackage = mCurrentWebViewPackage;
-            if (webViewReady) {
-            } else if (!mAnyWebViewInstalled) {
-                webViewStatus = WebViewFactory.LIBLOAD_FAILED_LISTING_WEBVIEW_PACKAGES;
-            } else {
-                // Either the current relro creation  isn't done yet, or the new relro creatioin
-                // hasn't kicked off yet (the last relro creation used an out-of-date WebView).
-                webViewStatus = WebViewFactory.LIBLOAD_FAILED_WAITING_FOR_RELRO;
-                Slog.e(TAG, "Timed out waiting for relro creation, relros started "
-                        + mNumRelroCreationsStarted
-                        + " relros finished " + mNumRelroCreationsFinished
-                        + " package dirty? " + mWebViewPackageDirty);
-            }
-        }
-        if (!webViewReady) Slog.w(TAG, "creating relro file timed out");
-        return new WebViewProviderResponse(webViewPackage, webViewStatus);
-    }
-
-    PackageInfo getCurrentWebViewPackage() {
-        synchronized(mLock) {
-            return mCurrentWebViewPackage;
-        }
-    }
-
-    /**
-     * Returns whether WebView is ready and is not going to go through its preparation phase
-     * again directly.
-     */
-    private boolean webViewIsReadyLocked() {
-        return !mWebViewPackageDirty
-            && (mNumRelroCreationsStarted == mNumRelroCreationsFinished)
-            // The current package might be replaced though we haven't received an intent
-            // declaring this yet, the following flag makes anyone loading WebView to wait in
-            // this case.
-            && mAnyWebViewInstalled;
-    }
-
-    private void checkIfRelrosDoneLocked() {
-        if (mNumRelroCreationsStarted == mNumRelroCreationsFinished) {
-            if (mWebViewPackageDirty) {
-                mWebViewPackageDirty = false;
-                // If we have changed provider since we started the relro creation we need to
-                // redo the whole process using the new package instead.
-                try {
-                    PackageInfo newPackage = findPreferredWebViewPackage();
-                    onWebViewProviderChanged(newPackage);
-                } catch (WebViewPackageMissingException e) {
-                    mCurrentWebViewPackage = null;
-                    // If we can't find any valid WebView package we are now in a state where
-                    // mAnyWebViewInstalled is false, so loading WebView will be blocked and we
-                    // should simply wait until we receive an intent declaring a new package was
-                    // installed.
-                }
-            } else {
-                mLock.notifyAll();
-            }
-        }
-    }
-
-    /**
-     * Returns whether this provider is valid for use as a WebView provider.
-     */
-    boolean isValidProvider(WebViewProviderInfo configInfo, PackageInfo packageInfo) {
-        return VALIDITY_OK == validityResult(configInfo, packageInfo);
-    }
-
-    private int validityResult(WebViewProviderInfo configInfo, PackageInfo packageInfo) {
-        // Ensure the provider targets this framework release (or a later one).
-        if (!UserPackage.hasCorrectTargetSdkVersion(packageInfo)) {
-            return VALIDITY_INCORRECT_SDK_VERSION;
-        }
-        if (!versionCodeGE(packageInfo.getLongVersionCode(), getMinimumVersionCode())
-                && !mSystemInterface.systemIsDebuggable()) {
-            // Webview providers may be downgraded arbitrarily low, prevent that by enforcing
-            // minimum version code. This check is only enforced for user builds.
-            return VALIDITY_INCORRECT_VERSION_CODE;
-        }
-        if (!providerHasValidSignature(configInfo, packageInfo, mSystemInterface)) {
-            return VALIDITY_INCORRECT_SIGNATURE;
-        }
-        if (WebViewFactory.getWebViewLibrary(packageInfo.applicationInfo) == null) {
-            return VALIDITY_NO_LIBRARY_FLAG;
-        }
-        return VALIDITY_OK;
-    }
-
-    /**
-     * Both versionCodes should be from a WebView provider package implemented by Chromium.
-     * VersionCodes from other kinds of packages won't make any sense in this method.
-     *
-     * An introduction to Chromium versionCode scheme:
-     * "BBBBPPPAX"
-     * BBBB: 4 digit branch number. It monotonically increases over time.
-     * PPP: patch number in the branch. It is padded with zeroes to the left. These three digits
-     * may change their meaning in the future.
-     * A: architecture digit.
-     * X: A digit to differentiate APKs for other reasons.
-     *
-     * This method takes the "BBBB" of versionCodes and compare them.
-     *
-     * @return true if versionCode1 is higher than or equal to versionCode2.
-     */
-    private static boolean versionCodeGE(long versionCode1, long versionCode2) {
-        long v1 = versionCode1 / 100000;
-        long v2 = versionCode2 / 100000;
-
-        return v1 >= v2;
-    }
-
-    /**
-     * Gets the minimum version code allowed for a valid provider. It is the minimum versionCode
-     * of all available-by-default WebView provider packages. If there is no such WebView provider
-     * package on the system, then return -1, which means all positive versionCode WebView packages
-     * are accepted.
-     *
-     * Note that this is a private method in WebViewUpdater that handles a variable
-     * (mMinimumVersionCode) which is shared between threads. Furthermore, this method does not
-     * hold mLock meaning that we must take extra care to ensure this method is thread-safe.
-     */
-    private long getMinimumVersionCode() {
-        if (mMinimumVersionCode > 0) {
-            return mMinimumVersionCode;
-        }
-
-        long minimumVersionCode = -1;
-        for (WebViewProviderInfo provider : mSystemInterface.getWebViewPackages()) {
-            if (provider.availableByDefault) {
-                try {
-                    long versionCode =
-                        mSystemInterface.getFactoryPackageVersion(provider.packageName);
-                    if (minimumVersionCode < 0 || versionCode < minimumVersionCode) {
-                        minimumVersionCode = versionCode;
-                    }
-                } catch (NameNotFoundException e) {
-                    // Safe to ignore.
-                }
-            }
-        }
-
-        mMinimumVersionCode = minimumVersionCode;
-        return mMinimumVersionCode;
-    }
-
-    private static boolean providerHasValidSignature(WebViewProviderInfo provider,
-            PackageInfo packageInfo, SystemInterface systemInterface) {
-        // Skip checking signatures on debuggable builds, for development purposes.
-        if (systemInterface.systemIsDebuggable()) return true;
-
-        // Allow system apps to be valid providers regardless of signature.
-        if (packageInfo.applicationInfo.isSystemApp()) return true;
-
-        // We don't support packages with multiple signatures.
-        if (packageInfo.signatures.length != 1) return false;
-
-        // If any of the declared signatures match the package signature, it's valid.
-        for (Signature signature : provider.signatures) {
-            if (signature.equals(packageInfo.signatures[0])) return true;
-        }
-
-        return false;
-    }
-
-    void dumpState(PrintWriter pw) {
-        synchronized (mLock) {
-            if (mCurrentWebViewPackage == null) {
-                pw.println("  Current WebView package is null");
-            } else {
-                pw.println(String.format("  Current WebView package (name, version): (%s, %s)",
-                        mCurrentWebViewPackage.packageName,
-                        mCurrentWebViewPackage.versionName));
-            }
-            pw.println(String.format("  Minimum targetSdkVersion: %d",
-                    UserPackage.MINIMUM_SUPPORTED_SDK));
-            pw.println(String.format("  Minimum WebView version code: %d",
-                  mMinimumVersionCode));
-            pw.println(String.format("  Number of relros started: %d",
-                    mNumRelroCreationsStarted));
-            pw.println(String.format("  Number of relros finished: %d",
-                        mNumRelroCreationsFinished));
-            pw.println(String.format("  WebView package dirty: %b", mWebViewPackageDirty));
-            pw.println(String.format("  Any WebView package installed: %b",
-                    mAnyWebViewInstalled));
-
-            try {
-                PackageInfo preferredWebViewPackage = findPreferredWebViewPackage();
-                pw.println(String.format(
-                        "  Preferred WebView package (name, version): (%s, %s)",
-                        preferredWebViewPackage.packageName,
-                        preferredWebViewPackage.versionName));
-            } catch (WebViewPackageMissingException e) {
-                pw.println(String.format("  Preferred WebView package: none"));
-            }
-
-            dumpAllPackageInformationLocked(pw);
-        }
-    }
-
-    private void dumpAllPackageInformationLocked(PrintWriter pw) {
-        WebViewProviderInfo[] allProviders = mSystemInterface.getWebViewPackages();
-        pw.println("  WebView packages:");
-        for (WebViewProviderInfo provider : allProviders) {
-            List<UserPackage> userPackages =
-                    mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider);
-            PackageInfo systemUserPackageInfo =
-                    userPackages.get(UserHandle.USER_SYSTEM).getPackageInfo();
-            if (systemUserPackageInfo == null) {
-                pw.println(String.format("    %s is NOT installed.", provider.packageName));
-                continue;
-            }
-
-            int validity = validityResult(provider, systemUserPackageInfo);
-            String packageDetails = String.format(
-                    "versionName: %s, versionCode: %d, targetSdkVersion: %d",
-                    systemUserPackageInfo.versionName,
-                    systemUserPackageInfo.getLongVersionCode(),
-                    systemUserPackageInfo.applicationInfo.targetSdkVersion);
-            if (validity == VALIDITY_OK) {
-                boolean installedForAllUsers = isInstalledAndEnabledForAllUsers(
-                        mSystemInterface.getPackageInfoForProviderAllUsers(mContext, provider));
-                pw.println(String.format(
-                        "    Valid package %s (%s) is %s installed/enabled for all users",
-                        systemUserPackageInfo.packageName,
-                        packageDetails,
-                        installedForAllUsers ? "" : "NOT"));
-            } else {
-                pw.println(String.format("    Invalid package %s (%s), reason: %s",
-                        systemUserPackageInfo.packageName,
-                        packageDetails,
-                        getInvalidityReason(validity)));
-            }
-        }
-    }
-
-    private static String getInvalidityReason(int invalidityReason) {
-        switch (invalidityReason) {
-            case VALIDITY_INCORRECT_SDK_VERSION:
-                return "SDK version too low";
-            case VALIDITY_INCORRECT_VERSION_CODE:
-                return "Version code too low";
-            case VALIDITY_INCORRECT_SIGNATURE:
-                return "Incorrect signature";
-            case VALIDITY_NO_LIBRARY_FLAG:
-                return "No WebView-library manifest flag";
-            default:
-                return "Unexcepted validity-reason";
-        }
-    }
-
-}