WebViewUpdateManager: handle devices without WebView properly.

Devices without FEATURE_WEBVIEW (Wear) don't run the
WebViewUpdateService and so looking up the service binder via
SystemServiceRegistry fails. This returns null in most cases but for
system processes this triggers a WTF, and was causing the Wear settings
app to crash.

Instead of trying to handle WebViewUpdateManager being null, guard all
the usages with an explicit check for whether WebView is supported on
the device, and update the API docs to clarify this requirement.

Bug: 319292658
Bug: 360768638
Test: atest CtsWebkitTestCases
Flag: android.webkit.update_service_ipc_wrapper
Change-Id: I13f0ddde49b3866ceb747a1d1b11e45504f05640

6 files changed, 28 insertions, 18 deletions

diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index ffcb1cbec94e..ce8c8ff8ce4d 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -33,6 +33,7 @@ import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.PermissionMethod;
 import android.annotation.PermissionName;
+import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
 import android.annotation.StringDef;
 import android.annotation.StringRes;
@@ -6677,6 +6678,8 @@ public abstract class Context {
      * Use with {@link #getSystemService(String)} to retrieve a {@link
      * android.webkit.WebViewUpdateManager} for accessing the WebView update service.
      *
+     * <p>This can only be used on devices with {@link PackageManager#FEATURE_WEBVIEW}.
+     *
      * @see #getSystemService(String)
      * @see android.webkit.WebViewUpdateManager
      * @hide
@@ -6684,6 +6687,7 @@ public abstract class Context {
     @FlaggedApi(android.webkit.Flags.FLAG_UPDATE_SERVICE_IPC_WRAPPER)
     @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
     @SuppressLint("ServiceName")
+    @RequiresFeature(PackageManager.FEATURE_WEBVIEW)
     public static final String WEBVIEW_UPDATE_SERVICE = "webviewupdate";
 
     /**
diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index f336b5d8a727..ffe8c80023c4 100644
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -3088,11 +3088,11 @@ public class WebView extends AbsoluteLayout
         }
 
         if (Flags.updateServiceIpcWrapper()) {
-            WebViewUpdateManager manager = WebViewUpdateManager.getInstance();
-            if (manager == null) {
+            if (WebViewFactory.isWebViewSupported()) {
+                return WebViewUpdateManager.getInstance().getCurrentWebViewPackage();
+            } else {
                 return null;
             }
-            return manager.getCurrentWebViewPackage();
         } else {
             IWebViewUpdateService service = WebViewFactory.getUpdateService();
             if (service == null) {
diff --git a/core/java/android/webkit/WebViewFactory.java b/core/java/android/webkit/WebViewFactory.java
index c53a0e158dea..829a519e65a7 100644
--- a/core/java/android/webkit/WebViewFactory.java
+++ b/core/java/android/webkit/WebViewFactory.java
@@ -208,7 +208,7 @@ public final class WebViewFactory {
         public MissingWebViewPackageException(Exception e) { super(e); }
     }
 
-    private static boolean isWebViewSupported() {
+    static boolean isWebViewSupported() {
         // No lock; this is a benign race as Boolean's state is final and the PackageManager call
         // will always return the same value.
         if (sWebViewSupported == null) {
diff --git a/core/java/android/webkit/WebViewUpdateManager.java b/core/java/android/webkit/WebViewUpdateManager.java
index dd48df975906..0eb710015ea9 100644
--- a/core/java/android/webkit/WebViewUpdateManager.java
+++ b/core/java/android/webkit/WebViewUpdateManager.java
@@ -19,12 +19,14 @@ package android.webkit;
 import android.annotation.FlaggedApi;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
 import android.annotation.SuppressLint;
 import android.annotation.SystemApi;
 import android.app.SystemServiceRegistry;
 import android.content.Context;
 import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
 import android.os.RemoteException;
 
 /** @hide */
@@ -43,8 +45,11 @@ public final class WebViewUpdateManager {
      *
      * This exists for the benefit of callsites without a {@link Context}; prefer
      * {@link Context#getSystemService(Class)} otherwise.
+     *
+     * This can only be used on devices with {@link PackageManager#FEATURE_WEBVIEW}.
      */
     @SuppressLint("ManagerLookup") // service opts in to getSystemServiceWithNoContext()
+    @RequiresFeature(PackageManager.FEATURE_WEBVIEW)
     public static @Nullable WebViewUpdateManager getInstance() {
         return (WebViewUpdateManager) SystemServiceRegistry.getSystemServiceWithNoContext(
                 Context.WEBVIEW_UPDATE_SERVICE);
diff --git a/core/java/android/webkit/WebViewUpdateService.java b/core/java/android/webkit/WebViewUpdateService.java
index 6f53ddeafef1..01af182a10fa 100644
--- a/core/java/android/webkit/WebViewUpdateService.java
+++ b/core/java/android/webkit/WebViewUpdateService.java
@@ -34,11 +34,11 @@ public final class WebViewUpdateService {
      */
     public static WebViewProviderInfo[] getAllWebViewPackages() {
         if (Flags.updateServiceIpcWrapper()) {
-            WebViewUpdateManager manager = WebViewUpdateManager.getInstance();
-            if (manager == null) {
+            if (WebViewFactory.isWebViewSupported()) {
+                return WebViewUpdateManager.getInstance().getAllWebViewPackages();
+            } else {
                 return new WebViewProviderInfo[0];
             }
-            return manager.getAllWebViewPackages();
         } else {
             IWebViewUpdateService service = getUpdateService();
             if (service == null) {
@@ -57,11 +57,11 @@ public final class WebViewUpdateService {
      */
     public static WebViewProviderInfo[] getValidWebViewPackages() {
         if (Flags.updateServiceIpcWrapper()) {
-            WebViewUpdateManager manager = WebViewUpdateManager.getInstance();
-            if (manager == null) {
+            if (WebViewFactory.isWebViewSupported()) {
+                return WebViewUpdateManager.getInstance().getValidWebViewPackages();
+            } else {
                 return new WebViewProviderInfo[0];
             }
-            return manager.getValidWebViewPackages();
         } else {
             IWebViewUpdateService service = getUpdateService();
             if (service == null) {
@@ -80,11 +80,11 @@ public final class WebViewUpdateService {
      */
     public static String getCurrentWebViewPackageName() {
         if (Flags.updateServiceIpcWrapper()) {
-            WebViewUpdateManager manager = WebViewUpdateManager.getInstance();
-            if (manager == null) {
+            if (WebViewFactory.isWebViewSupported()) {
+                return WebViewUpdateManager.getInstance().getCurrentWebViewPackageName();
+            } else {
                 return null;
             }
-            return manager.getCurrentWebViewPackageName();
         } else {
             IWebViewUpdateService service = getUpdateService();
             if (service == null) {
diff --git a/packages/SettingsLib/src/com/android/settingslib/Utils.java b/packages/SettingsLib/src/com/android/settingslib/Utils.java
index b02b0c454644..1e5833564d39 100644
--- a/packages/SettingsLib/src/com/android/settingslib/Utils.java
+++ b/packages/SettingsLib/src/com/android/settingslib/Utils.java
@@ -495,7 +495,7 @@ public class Utils {
                 || packageName.equals(sServicesSystemSharedLibPackageName)
                 || packageName.equals(sSharedSystemSharedLibPackageName)
                 || packageName.equals(PrintManager.PRINT_SPOOLER_PACKAGE_NAME)
-                || (updateServiceV2() && packageName.equals(getDefaultWebViewPackageName()))
+                || (updateServiceV2() && packageName.equals(getDefaultWebViewPackageName(pm)))
                 || isDeviceProvisioningPackage(resources, packageName);
     }
 
@@ -511,7 +511,7 @@ public class Utils {
 
     /** Fetch the package name of the default WebView provider. */
     @Nullable
-    private static String getDefaultWebViewPackageName() {
+    private static String getDefaultWebViewPackageName(PackageManager pm) {
         if (sDefaultWebViewPackageName != null) {
             return sDefaultWebViewPackageName;
         }
@@ -519,9 +519,10 @@ public class Utils {
         WebViewProviderInfo provider = null;
 
         if (android.webkit.Flags.updateServiceIpcWrapper()) {
-            WebViewUpdateManager manager = WebViewUpdateManager.getInstance();
-            if (manager != null) {
-                provider = manager.getDefaultWebViewPackage();
+            if (pm.hasSystemFeature(PackageManager.FEATURE_WEBVIEW)) {
+                // WebViewUpdateManager.getInstance() will not return null on devices with
+                // FEATURE_WEBVIEW.
+                provider = WebViewUpdateManager.getInstance().getDefaultWebViewPackage();
             }
         } else {
             try {