Only send events to renderers that are listening to an event....

chrome/browser/renderer_host/browser_render_process_host.cc

 // Copyright (c) 2006-2009 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 
 #include "build/build_config.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/linked_ptr.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/rand_util.h"
 #include "base/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/singleton.h"
 #include "base/string_util.h"
 #include "base/thread.h"
 #include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/extension_message_service.h"
 #include "chrome/browser/extensions/user_script_master.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/plugin_service.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/render_widget_helper.h"
 #include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/browser/renderer_host/renderer_security_policy.h"
 #include "chrome/browser/renderer_host/resource_message_filter.h"
 #include "chrome/browser/renderer_host/web_cache_manager.h"
@@ skipping 545 matching lines @@
 void BrowserRenderProcessHost::OnMessageReceived(const IPC::Message& msg) {
   if (msg.routing_id() == MSG_ROUTING_CONTROL) {
     // dispatch control messages
     bool msg_is_ok = true;
     IPC_BEGIN_MESSAGE_MAP_EX(BrowserRenderProcessHost, msg, msg_is_ok)
       IPC_MESSAGE_HANDLER(ViewHostMsg_PageContents, OnPageContents)
       IPC_MESSAGE_HANDLER(ViewHostMsg_UpdatedCacheStats,
                           OnUpdatedCacheStats)
       IPC_MESSAGE_HANDLER(ViewHostMsg_SuddenTerminationChanged,
                           SuddenTerminationChanged);
+      IPC_MESSAGE_HANDLER(ViewHostMsg_ExtensionAddListener,
+                          OnExtensionAddListener)
+      IPC_MESSAGE_HANDLER(ViewHostMsg_ExtensionRemoveListener,
+                          OnExtensionRemoveListener)
       IPC_MESSAGE_UNHANDLED_ERROR()
     IPC_END_MESSAGE_MAP_EX()
 
     if (!msg_is_ok) {
       // The message had a handler, but its de-serialization failed.
       // We consider this a capital crime. Kill the renderer if we have one.
       ReceivedBadMessage(msg.type());
     }
     return;
   }
@@ skipping 189 matching lines @@
         SendUserScriptsUpdate(shared_memory);
       }
       break;
     }
     default: {
       NOTREACHED();
       break;
     }
   }
 }
+
+void BrowserRenderProcessHost::OnExtensionAddListener(
+    const std::string& event_name) {
+  URLRequestContext* context = profile()->GetRequestContext();
+  ExtensionMessageService* ems = ExtensionMessageService::GetInstance(context);
+  ems->AddEventListener(event_name, pid());
+}
+
+void BrowserRenderProcessHost::OnExtensionRemoveListener(
+    const std::string& event_name) {
+  URLRequestContext* context = profile()->GetRequestContext();
+  ExtensionMessageService* ems = ExtensionMessageService::GetInstance(context);
+  ems->RemoveEventListener(event_name, pid());
+}