Fix an issue that an invalid surface could be passed to MediaPlayerBridge

ui/gl/android/scoped_java_surface.cc

 // Copyright (c) 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 "ui/gl/android/scoped_java_surface.h"
 
 #include "base/logging.h"
 #include "jni/Surface_jni.h"
 #include "ui/gl/android/surface_texture.h"
 
@@ skipping 57 matching lines @@
   JNIEnv* env = base::android::AttachCurrentThread();
   j_surface_.Reset(env, other.j_surface_.Release());
   auto_release_ = other.auto_release_;
   is_protected_ = other.is_protected_;
 }
 
 bool ScopedJavaSurface::IsEmpty() const {
   return j_surface_.is_null();
 }
 
+bool ScopedJavaSurface::IsValid() const {
+  // Null surface are considered valid as it can be passed to a MediaPlayer.
+  if (IsEmpty())
+    return true;
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return JNI_Surface::Java_Surface_isValid(env, j_surface_.obj());

[no sievers, 2015/10/08 23:00:27]

Are you sure we need to check this? Or is it good enough to reset surface_ to
null in SetVideoSurface (i.e. you other change)?

This *seems* odd, because we don't really do that anywhere else we deal with
Surfaces. Before it's released ContentVideoView.surfaceDestroyed() should cause
us to reset our reference.

[qinmin, 2015/10/08 23:47:23]

removed this function. When surfaceDestroyed() is called, setVideoSurface(null)
should be called. In that case, we can just set surface_ to surface(which is
null).

+}
+
 // static
 ScopedJavaSurface ScopedJavaSurface::AcquireExternalSurface(jobject surface) {
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jobject> surface_ref;
   surface_ref.Reset(env, surface);
   gfx::ScopedJavaSurface scoped_surface(surface_ref);
   scoped_surface.auto_release_ = false;
   scoped_surface.is_protected_ = true;
   return scoped_surface;
 }
 
 }  // namespace gfx