Cache the current WebPreferences on RenderViewHostImpl (try #2).

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 2127 matching lines @@
       RenderWidgetHostImpl::GetAllRenderWidgetHosts());
   while (RenderWidgetHost* widget = widgets->GetNextHost()) {
     if (!widget->IsRenderView())
       continue;
 
     // Skip widgets in other processes.
     if (widget->GetProcess()->GetID() != GetID())
       continue;
 
     RenderViewHost* rvh = RenderViewHost::From(widget);
-    rvh->UpdateWebkitPreferences(rvh->GetWebkitPreferences());
+    rvh->OnWebkitPreferencesChanged();
   }
 }
 
 #if defined(ENABLE_WEBRTC)
 void RenderProcessHostImpl::OnRegisterAecDumpConsumer(int id) {
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(
           &RenderProcessHostImpl::RegisterAecDumpConsumerOnUIThread,
@@ skipping 186 matching lines @@
 }
 
 void RenderProcessHostImpl::OnDeletedGpuMemoryBuffer(
     gfx::GpuMemoryBufferType type,
     const gfx::GpuMemoryBufferId& id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   GpuMemoryBufferImpl::DeletedByChildProcess(type, id, GetHandle());
 }
 
 }  // namespace content