[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 filter, which triggers its deletion. Needs to be called when
+  // the corresponding RenderProcessHost cleans itself up, e.g. on renderer
+  // process exit.
+  static void RemoveFilter(GinJavaBridgeDispatcherHost* host);
+
  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_