Make extensions use ViewMsg_EnableIntrinsicWidthChangedMode.

chrome/browser/extensions/extension_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.
 
 #include "chrome/browser/extensions/extension_host.h"
 
 #include "app/resource_bundle.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
@@ skipping 327 matching lines @@
   return extension_host_type_;
 }
 
 void ExtensionHost::RenderViewCreated(RenderViewHost* render_view_host) {
   // TODO(mpcomplete): This is duplicated in DidNavigate, which means that
   // we'll create 2 EFDs for the first navigation. We should try to find a
   // better way to unify them.
   // See http://code.google.com/p/chromium/issues/detail?id=18240
   extension_function_dispatcher_.reset(
       new ExtensionFunctionDispatcher(render_view_host, this, url_));
+
+  render_view_host->Send(new ViewMsg_EnableIntrinsicWidthChangedMode(
+      render_view_host->routing_id()));
 }
 
 int ExtensionHost::GetBrowserWindowID() const {
   int window_id = -1;
   if (extension_host_type_ == ViewType::EXTENSION_TOOLSTRIP) {
     window_id = ExtensionTabUtil::GetWindowId(
         const_cast<ExtensionHost* >(this)->GetBrowser());
   } else if (extension_host_type_ == ViewType::EXTENSION_BACKGROUND_PAGE) {
     // Background page is not attached to any browser window, so pass -1.
     window_id = -1;
   } else {
     NOTREACHED();
   }
   return window_id;
 }