aura: Support SurfaceDestroyed() on Android

ui/platform_window/android/platform_window_android.cc

 // Copyright 2015 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 "ui/platform_window/android/platform_window_android.h"
 
 #include <android/input.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
@@ skipping 71 matching lines @@
   // 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_, device_pixel_ratio);
 }
 
 void PlatformWindowAndroid::SurfaceDestroyed(JNIEnv* env, jobject obj) {
   DCHECK(window_);
+  delegate_->OnAcceleratedWidgetDestroyed();
   ReleaseWindow();
-  delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 0.f);

[no sievers, 2015/10/16 20:38:59]

kNullAcceleratedWidget might be used in tests and causes an offscreen surface to
be created, so comparing against that in WTH to trigger the release might not be
a good idea. 

 }
 
 void PlatformWindowAndroid::SurfaceSetSize(JNIEnv* env,
                                            jobject obj,
                                            jint width,
                                            jint height,
                                            jfloat density) {
   size_ = gfx::Size(static_cast<int>(width), static_cast<int>(height));
   delegate_->OnBoundsChanged(gfx::Rect(size_));
 }
@@ skipping 110 matching lines @@
 
 void PlatformWindowAndroid::ConfineCursorToBounds(const gfx::Rect& bounds) {
   NOTIMPLEMENTED();
 }
 
 PlatformImeController* PlatformWindowAndroid::GetPlatformImeController() {
   return &platform_ime_controller_;
 }
 
 }  // namespace ui