Delay UpdateRect until the SwapBuffers callback when accelerated compositing is on.

content/browser/renderer_host/render_widget_helper.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 "content/browser/renderer_host/render_widget_helper.h"
 
 #include "base/bind.h"
 #include "base/eintr_wrapper.h"
 #include "base/threading/thread.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
@@ skipping 91 matching lines @@
                                           IPC::Message* msg) {
   base::TimeTicks time_start = base::TimeTicks::Now();
 
   for (;;) {
     UpdateMsgProxy* proxy = NULL;
     {
       base::AutoLock lock(pending_paints_lock_);
 
       UpdateMsgProxyMap::iterator it = pending_paints_.find(render_widget_id);
       if (it != pending_paints_.end()) {
-        proxy = it->second;
+        UpdateMsgProxyQueue &queue = it->second;
+        DCHECK(!queue.empty());
+        proxy = queue.front();
 
         // Flag the proxy as cancelled so that when it is run as a task it will
         // do nothing.
         proxy->cancelled = true;
 
-        pending_paints_.erase(it);
+        queue.pop_front();
+        if (queue.empty())
+          pending_paints_.erase(it);
       }
     }
 
     if (proxy) {
       *msg = proxy->message;
       DCHECK(msg->routing_id() == render_widget_id);
       return true;
     }
 
     // Calculate the maximum amount of time that we are willing to sleep.
     base::TimeDelta max_sleep_time =
         max_delay - (base::TimeTicks::Now() - time_start);
     if (max_sleep_time <= base::TimeDelta::FromMilliseconds(0))
       break;
 
     event_.TimedWait(max_sleep_time);
   }
 
   return false;
 }
 
 void RenderWidgetHelper::DidReceiveUpdateMsg(const IPC::Message& msg) {
   int render_widget_id = msg.routing_id();
 
-  UpdateMsgProxy* proxy = NULL;
+  UpdateMsgProxy* proxy = new UpdateMsgProxy(this, msg);
   {
     base::AutoLock lock(pending_paints_lock_);
 
-    // Visual Studio 2010 has problems converting NULL to the null pointer for
-    // std::pair.  See http://connect.microsoft.com/VisualStudio/feedback/details/520043/error-converting-from-null-to-a-pointer-type-in-std-pair
-    // It will work if we pass nullptr.
-#if defined(_MSC_VER) && _MSC_VER >= 1600
-    RenderWidgetHelper::UpdateMsgProxy* null_proxy = nullptr;
-#else
-    RenderWidgetHelper::UpdateMsgProxy* null_proxy = NULL;
-#endif
-    UpdateMsgProxyMap::value_type new_value(render_widget_id, null_proxy);
-
-    // We expect only a single PaintRect message at a time.  Optimize for the
-    // case that we don't already have an entry by using the 'insert' method.
-    std::pair<UpdateMsgProxyMap::iterator, bool> result =
-        pending_paints_.insert(new_value);
-    if (!result.second) {
-      NOTREACHED() << "Unexpected PaintRect message!";
-      return;
-    }
-
-    result.first->second = (proxy = new UpdateMsgProxy(this, msg));
+    pending_paints_[render_widget_id].push_back(proxy);
   }
 
   // Notify anyone waiting on the UI thread that there is a new entry in the
   // proxy map.  If they don't find the entry they are looking for, then they
   // will just continue waiting.
   event_.Signal();
 
   // The proxy will be deleted when it is run as a task.
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, proxy);
 }
 
 void RenderWidgetHelper::OnDiscardUpdateMsg(UpdateMsgProxy* proxy) {
   const IPC::Message& msg = proxy->message;
 
   // Remove the proxy from the map now that we are going to handle it normally.
   {
     base::AutoLock lock(pending_paints_lock_);
 
     UpdateMsgProxyMap::iterator it = pending_paints_.find(msg.routing_id());
     DCHECK(it != pending_paints_.end());
-    DCHECK(it->second == proxy);
+    UpdateMsgProxyQueue &queue = it->second;
+    DCHECK(queue.front() == proxy);
 
-    pending_paints_.erase(it);
+    queue.pop_front();
+    if (queue.empty())
+      pending_paints_.erase(it);
   }
 }
 
 void RenderWidgetHelper::OnDispatchUpdateMsg(UpdateMsgProxy* proxy) {
   OnDiscardUpdateMsg(proxy);
 
   // It is reasonable for the host to no longer exist.
   content::RenderProcessHost* host =
       content::RenderProcessHost::FromID(render_process_id_);
   if (host)
@@ skipping 150 matching lines @@
 gfx::PluginWindowHandle RenderWidgetHelper::LookupCompositingSurface(
     int render_widget_id) {
   base::AutoLock locked(view_compositing_surface_map_lock_);
   ViewCompositingSurfaceMap::iterator it =
       view_compositing_surface_map_.find(render_widget_id);
   if (it == view_compositing_surface_map_.end())
     return gfx::kNullPluginWindow;
 
   return it->second;
 }