Get rid of extensions dependency from content\browser.

chrome/browser/tab_contents/background_contents.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/tab_contents/background_contents.h"
 
 #include "chrome/browser/background_contents_service.h"
 #include "chrome/browser/desktop_notification_handler.h"
+#include "chrome/browser/extensions/extension_message_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_preferences_util.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_factory.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/common/view_types.h"
 #include "content/browser/browsing_instance.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/site_instance.h"
@@ skipping 165 matching lines @@
                                         base::TerminationStatus status,
                                         int error_code) {
   // Our RenderView went away, so we should go away also, so killing the process
   // via the TaskManager doesn't permanently leave a BackgroundContents hanging
   // around the system, blocking future instances from being created
   // (http://crbug.com/65189).
   delete this;
 }
 
 bool BackgroundContents::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(BackgroundContents, message)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_PostMessage, OnPostMessage)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
   // Forward desktop notification IPCs if any to the
   // DesktopNotificationHandler.
-  return desktop_notification_handler_->OnMessageReceived(message);
+  if (!handled)
+   handled = desktop_notification_handler_->OnMessageReceived(message);
+  return handled;
 }
 
 RendererPreferences BackgroundContents::GetRendererPrefs(
     Profile* profile) const {
   RendererPreferences preferences;
   renderer_preferences_util::UpdateFromSystemSettings(&preferences, profile);
   return preferences;
 }
 
 WebPreferences BackgroundContents::GetWebkitPrefs() {
@@ skipping 56 matching lines @@
 BackgroundContents*
 BackgroundContents::GetBackgroundContentsByID(int render_process_id,
                                               int render_view_id) {
   RenderViewHost* render_view_host =
       RenderViewHost::FromID(render_process_id, render_view_id);
   if (!render_view_host)
     return NULL;
 
   return render_view_host->delegate()->GetAsBackgroundContents();
 }
+
+void BackgroundContents::OnPostMessage(int port_id,
+                                       const std::string& message) {
+  Profile* profile = render_view_host_->process()->profile();
+  if (profile->GetExtensionMessageService()) {
+    profile->GetExtensionMessageService()->PostMessageFromRenderer(
+        port_id, message);
+  }
+}