Mac/gpu: Don't show uninitialized surfaces while resizing plugins / composited tabs.

chrome/browser/renderer_host/accelerated_surface_container_manager_mac.cc

 // Copyright (c) 2010 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/renderer_host/accelerated_surface_container_manager_mac.h"
 
 #include "base/logging.h"
 #include "chrome/browser/renderer_host/accelerated_surface_container_mac.h"
 #include "webkit/glue/plugins/webplugin.h"
 
@@ skipping 81 matching lines @@
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(move.window);
   if (container)
     container->SetGeometry(move);
 }
 
 void AcceleratedSurfaceContainerManagerMac::Draw(CGLContextObj context,
                                                  gfx::PluginWindowHandle id) {
   AutoLock lock(lock_);
 
   glColorMask(true, true, true, true);
-  glClearColor(0, 0, 0, 0);
+  // Should match the clear color of RenderWidgetHostViewMac.
+  glClearColor(255, 255, 255, 255);

[stuartmorgan, 2010/11/05 17:35:26]

This needs to be conditional on the surface being opaque, with the transparent
version still using 0, 0, 0, 0. We have an opaque flag at this layer, so we can
do it correctly now and not have this bite us later when we get transparent
support.

(I don't remember whether we set opaque for plugins right now; if not we should
change that and put a TODO there.)

+  // TODO(thakis): Clearing the whole color buffer is wasteful, since most of
+  // it is overwritten by the surface.
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_BLEND);
 
   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 
   AcceleratedSurfaceContainerMac* container = MapIDToContainer(id);
   CHECK(container);
   container->Draw(context);
 
@@ skipping 48 matching lines @@
         gfx::PluginWindowHandle id) const {
   PluginWindowToContainerMap::const_iterator i =
       plugin_window_to_container_map_.find(id);
   if (i != plugin_window_to_container_map_.end())
     return i->second;
 
   LOG(ERROR) << "Request for plugin container for unknown window id " << id;
 
   return NULL;
 }