RenderWidget::WasRestored should repaint the view when accelerated compositin...

chrome/browser/renderer_host/render_widget_host.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/render_widget_host.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/histogram.h"
 #include "base/keyboard_codes.h"
@@ skipping 207 matching lines @@
 
 void RenderWidgetHost::WasRestored() {
   // When we create the widget, it is created as *not* hidden.
   if (!is_hidden_)
     return;
   is_hidden_ = false;
 
   BackingStore* backing_store = BackingStoreManager::Lookup(this);
   // If we already have a backing store for this widget, then we don't need to
   // repaint on restore _unless_ we know that our backing store is invalid.
+  // When accelerated compositing is on, we must always repaint, even when
+  // the backing store exists.
   bool needs_repainting;
-  if (needs_repainting_on_restore_ || !backing_store) {
+  if (needs_repainting_on_restore_ || !backing_store ||
+      is_gpu_rendering_active()) {
     needs_repainting = true;
     needs_repainting_on_restore_ = false;
   } else {
     needs_repainting = false;
   }
   Send(new ViewMsg_WasRestored(routing_id_, needs_repainting));
 
   process_->WidgetRestored();
 
   bool is_visible = true;
@@ skipping 932 matching lines @@
     // of this key event.
     if (!processed && !is_hidden_ && !front_item.skip_in_browser) {
       UnhandledKeyboardEvent(front_item);
 
       // WARNING: This RenderWidgetHost can be deallocated at this point
       // (i.e.  in the case of Ctrl+W, where the call to
       // UnhandledKeyboardEvent destroys this RenderWidgetHost).
     }
   }
 }