base: Add ScopedJavaLocalFrame class.

mojo/services/native_viewport/native_viewport_android.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/services/native_viewport/native_viewport_android.h"
 
 #include <android/input.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
@@ skipping 42 matching lines @@
 }
 
 void NativeViewportAndroid::Destroy(JNIEnv* env, jobject obj) {
   delegate_->OnDestroyed();
 }
 
 void NativeViewportAndroid::SurfaceCreated(JNIEnv* env,
                                            jobject obj,
                                            jobject jsurface) {
   base::android::ScopedJavaLocalRef<jobject> protector(env, jsurface);
-  window_ = ANativeWindow_fromSurface(env, jsurface);
+  // Note: This ensures that any local references used by
+  // ANativeWindow_fromSurface are released immediately. This is needed as a
+  // workaround for https://code.google.com/p/android/issues/detail?id=68174
+  {
+    base::android::ScopedJavaLocalFrame scoped_local_reference_frame(env);
+    window_ = ANativeWindow_fromSurface(env, jsurface);
+  }
   delegate_->OnAcceleratedWidgetAvailable(window_);
 }
 
 void NativeViewportAndroid::SurfaceDestroyed(JNIEnv* env, jobject obj) {
   DCHECK(window_);
   ReleaseWindow();
 }
 
 void NativeViewportAndroid::SurfaceSetSize(JNIEnv* env, jobject obj,
                                            jint width, jint height) {
@@ skipping 72 matching lines @@
 // static
 scoped_ptr<NativeViewport> NativeViewport::Create(
     shell::Context* context,
     NativeViewportDelegate* delegate) {
   return scoped_ptr<NativeViewport>(
       new NativeViewportAndroid(context, delegate)).Pass();
 }
 
 }  // namespace services
 }  // namespace mojo