Rewire Android WebView's compositor changed signal.

android_webview/native/aw_contents.h

 // Copyright (c) 2012 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 ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_
 #define ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_
 
 #include <jni.h>
 
 #include <list>
@@ skipping 328 matching lines @@
   // Geolocation API support
   void ShowGeolocationPrompt(const GURL& origin, base::Callback<void(bool)>);
   void HideGeolocationPrompt(const GURL& origin);
 
   void SetDipScaleInternal(float dip_scale);
 
   void SetAwGLFunctor(AwGLFunctor* functor);
 
   JavaObjectWeakGlobalRef java_ref_;
   AwGLFunctor* functor_;
+  std::unique_ptr<content::WebContents> web_contents_;
   BrowserViewRenderer browser_view_renderer_;  // Must outlive |web_contents_|.

[boliu, 2016/06/13 15:30:44]

uhh... the comment is clearly wrong now

maybe should figure out why it was added and see if it's still the case?

[hush (inactive), 2016/06/14 23:48:29]

I put it back to place. It was added so that SynchronousCompositorClient  (BVR)
outlives SynchronousCompositor. (web_contents)
It's a great guarantee to have. https://codereview.chromium.org/1385543003/

   std::unique_ptr<AwWebContentsDelegate> web_contents_delegate_;
   std::unique_ptr<AwContentsClientBridge> contents_client_bridge_;
-  std::unique_ptr<content::WebContents> web_contents_;
   std::unique_ptr<AwRenderViewHostExt> render_view_host_ext_;
   std::unique_ptr<FindHelper> find_helper_;
   std::unique_ptr<IconHelper> icon_helper_;
   std::unique_ptr<AwContents> pending_contents_;
   std::unique_ptr<AwPdfExporter> pdf_exporter_;
   std::unique_ptr<PermissionRequestHandler> permission_request_handler_;
   scoped_refptr<AwMessagePortMessageFilter> message_port_message_filter_;
 
   // GURL is supplied by the content layer as requesting frame.
   // Callback is supplied by the content layer, and is invoked with the result
   // from the permission prompt.
   typedef std::pair<const GURL, base::Callback<void(bool)> > OriginCallback;
   // The first element in the list is always the currently pending request.
   std::list<OriginCallback> pending_geolocation_prompts_;
 
   GLViewRendererManager::Key renderer_manager_key_;
 
   DISALLOW_COPY_AND_ASSIGN(AwContents);
 };
 
 bool RegisterAwContents(JNIEnv* env);
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_H_