[Android] Fix GinJavaBridgeMessageFilter registration issue in Java Bridge.

content/browser/android/java/gin_java_bridge_message_filter.h

 // 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.
 
 #ifndef CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BRIDGE_MESSAGE_FILTER_H_
 #define CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BRIDGE_MESSAGE_FILTER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 27 matching lines @@
       const IPC::Message& message) override;
 
   // Called on the UI thread.
   void AddRoutingIdForHost(GinJavaBridgeDispatcherHost* host,
                            RenderFrameHost* render_frame_host);
   void RemoveHost(GinJavaBridgeDispatcherHost* host);
 
   static scoped_refptr<GinJavaBridgeMessageFilter> FromHost(
       GinJavaBridgeDispatcherHost* host, bool create_if_not_exists);
 
+  // Removes the user data for the |host| from the associated RenderProcessHost.

[mnaganov (inactive), 2015/12/29 16:55:28]

Please change the comment to: "Removes the filter, which triggers its deletion.
Needs to be called when the corresponding RenderProcessHost cleans itself up,
e.g. on renderer process exit."

Your version contains too many unnecessary details :)

[Pritam Nikam, 2015/12/30 12:05:36]

Done.

+  // It need to be called from |host| when communication channel between RPH and
+  // sandbox render process gets exited and eventually triggers the deletion of
+  // this filter. Once new sandbox render process gets up and ready a new
+  // message filter gets created and registered to receive Java bridge IPC
+  // messages.
+  void RemoveUserData(const GinJavaBridgeDispatcherHost* host);

[mnaganov (inactive), 2015/12/29 16:55:28]

Please remove `const` for consistency with the rest of the methods.

[mnaganov (inactive), 2015/12/29 16:55:28]

I would prefer to rename `RemoveUserData` into `RemoveFilter` and make it
static. This way, you will not need to retrieve the filter first in
`RenderProcessGone`. It's perfectly OK to call
`SupportsUserData::RemoveUserData` even if the map contains no corresponding
key.

[Pritam Nikam, 2015/12/30 12:05:36]

Done.

[Pritam Nikam, 2015/12/30 12:05:36]

Done.

+
  private:
   friend class BrowserThread;
   friend class base::DeleteHelper<GinJavaBridgeMessageFilter>;
 
   // ContentViewCore (who owns GinJavaBridgeDispatcherHost) outlives
   // WebContents, and GinJavaBridgeDispatcherHost removes itself from the map on
   // WebContents destruction, so there is no risk that the pointer would become
   // stale.
   //
   // The filter keeps its own routing map of RenderFrames for two reasons:
@@ skipping 27 matching lines @@
   base::Lock hosts_lock_;
 
   // The routing id of the RenderFrameHost whose request we are processing.
   // Used on the background thread.
   int32_t current_routing_id_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BRIDGE_MESSAGE_FILTER_H_