Revert "Revert "Add support for booting with a boot classpath not fully AOTed.""

This reverts commit 14bfeddf2e434954f0ca36687ac0fc5dc6412bd3.

Reason for revert: Removes obsolete DCHECK
Bug: 119800099

Change-Id: Ia984f95300c6b96165f0179bfc2f66b012bf5dbe
diff --git a/libartbase/base/file_utils.cc b/libartbase/base/file_utils.cc
index 4953bab..2436e45 100644
--- a/libartbase/base/file_utils.cc
+++ b/libartbase/base/file_utils.cc
@@ -176,12 +176,16 @@
   return GetAndroidDirSafe("ANDROID_DATA", "/data", error_msg);
 }
 
+std::string GetDefaultBootImageLocation(const std::string& android_root) {
+  return StringPrintf("%s/framework/boot.art", android_root.c_str());
+}
+
 std::string GetDefaultBootImageLocation(std::string* error_msg) {
   std::string android_root = GetAndroidRootSafe(error_msg);
   if (android_root.empty()) {
     return "";
   }
-  return StringPrintf("%s/framework/boot.art", android_root.c_str());
+  return GetDefaultBootImageLocation(android_root);
 }
 
 void GetDalvikCache(const char* subdir, const bool create_if_absent, std::string* dalvik_cache,
diff --git a/libartbase/base/file_utils.h b/libartbase/base/file_utils.h
index bddfaa1..c8eca59 100644
--- a/libartbase/base/file_utils.h
+++ b/libartbase/base/file_utils.h
@@ -43,6 +43,9 @@
 // Returns an empty string if ANDROID_ROOT is not set.
 std::string GetDefaultBootImageLocation(std::string* error_msg);
 
+// Returns the default boot image location, based on the passed android root.
+std::string GetDefaultBootImageLocation(const std::string& android_root);
+
 // Returns the dalvik-cache location, with subdir appended. Returns the empty string if the cache
 // could not be found.
 std::string GetDalvikCache(const char* subdir);