Null check ContentViewCore::GetJavaObject

chromecast/browser/android/external_video_surface_container_impl.h

 // Copyright 2014 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.
 
 #ifndef CHROMECAST_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_IMPL_H_
 #define CHROMECAST_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_IMPL_H_
 
 #include <jni.h>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "content/public/browser/android/external_video_surface_container.h"
 
 namespace chromecast {
 namespace shell {
 
 class ExternalVideoSurfaceContainerImpl
     : public content::ExternalVideoSurfaceContainer {
  public:
   typedef base::Callback<void(int, jobject)> SurfaceCreatedCB;
   typedef base::Callback<void(int)> SurfaceDestroyedCB;
 
-  ExternalVideoSurfaceContainerImpl(content::WebContents* contents);
+  static ExternalVideoSurfaceContainerImpl* Create(
+      content::WebContents* web_contents);
 
   // ExternalVideoSurfaceContainer implementation.
   void RequestExternalVideoSurface(
       int player_id,
       const SurfaceCreatedCB& surface_created_cb,
       const SurfaceDestroyedCB& surface_destroyed_cb) override;
   int GetCurrentPlayerId() override;
   void ReleaseExternalVideoSurface(int player_id) override;
   void OnFrameInfoUpdated() override;
   void OnExternalVideoSurfacePositionChanged(
       int player_id, const gfx::RectF& rect) override;
 
   // Methods called from Java.
   void SurfaceCreated(
       JNIEnv* env, jobject obj, jint player_id, jobject jsurface);
   void SurfaceDestroyed(JNIEnv* env, jobject obj, jint player_id);
 
  private:
+  explicit ExternalVideoSurfaceContainerImpl(
+      base::android::ScopedJavaLocalRef<jobject> java_content_view_core);
   ~ExternalVideoSurfaceContainerImpl() override;
 
   base::android::ScopedJavaGlobalRef<jobject> jobject_;
 
   SurfaceCreatedCB surface_created_cb_;
   SurfaceDestroyedCB surface_destroyed_cb_;
 
  DISALLOW_COPY_AND_ASSIGN(ExternalVideoSurfaceContainerImpl);
 };
 
 bool RegisterExternalVideoSurfaceContainer(JNIEnv* env);
 
 }  // namespace shell
 }  // namespace chromecast
 
 #endif  // CHROMECAST_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_IMPL_H_