Fix resize issues when using threaded compositing

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 950 matching lines @@
   TRACE_EVENT0("gpu", "RenderWidget::didDeactivateCompositor");
 
   is_accelerated_compositing_active_ = false;
   Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
       routing_id_, is_accelerated_compositing_active_));
 
   if (using_asynchronous_swapbuffers_)
     using_asynchronous_swapbuffers_ = false;
 }
 
+void RenderWidget::didCommitAndDrawCompositorFrame()

[jam, 2011/11/17 22:56:12]

nit: here and below, brace bracket on the previous line per the chrome style
guide

+{
+}
+
+void RenderWidget::didCompleteSwapBuffers()
+{
+  if (update_reply_pending())
+    return;
+
+  if (!next_paint_flags_ && !plugin_window_moves_.size())

[jbates, 2012/04/16 23:41:35]

This will blow up if someone adds new flags to ViewHostMsg_UpdateRect_Flags.

+    return;
+
+  ViewHostMsg_UpdateRect_Params params;
+  params.view_size = size_;
+  params.resizer_rect = resizer_rect_;
+  params.plugin_window_moves.swap(plugin_window_moves_);
+  params.flags = next_paint_flags_;
+  params.scroll_offset = GetScrollOffset();
+  update_reply_pending_ = true;
+
+  Send(new ViewHostMsg_UpdateRect(routing_id_, params));
+  next_paint_flags_ = 0;
+}
+
 void RenderWidget::scheduleComposite() {
   if (WebWidgetHandlesCompositorScheduling())
     webwidget_->composite(false);
   else {
     // TODO(nduca): replace with something a little less hacky.  The reason this
     // hack is still used is because the Invalidate-DoDeferredUpdate loop
     // contains a lot of host-renderer synchronization logic that is still
     // important for the accelerated compositing case. The option of simply
     // duplicating all that code is less desirable than "faking out" the
     // invalidation path using a magical damage rect.
@@ skipping 494 matching lines @@
   }
 }
 
 bool RenderWidget::WillHandleMouseEvent(const WebKit::WebMouseEvent& event) {
   return false;
 }
 
 bool RenderWidget::WebWidgetHandlesCompositorScheduling() const {
   return false;
 }