Null-check of OnMsgDidActivateAcceleratedCompositing to avoid crash during ta...

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 "app/keyboard_codes.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
@@ skipping 969 matching lines @@
 
 void RenderWidgetHost::OnMsgDidActivateAcceleratedCompositing(bool activated) {
 #if defined(OS_MACOSX)
   bool old_state = is_accelerated_compositing_active_;
 #endif
   is_accelerated_compositing_active_ = activated;
 #if defined(OS_MACOSX)
   if (old_state != is_accelerated_compositing_active_ && view_)
     view_->GpuRenderingStateDidChange();
 #elif defined(OS_WIN)
-  view_->ShowCompositorHostWindow(is_accelerated_compositing_active_);
+  if (view_)
+    view_->ShowCompositorHostWindow(is_accelerated_compositing_active_);
 #elif defined(TOOLKIT_USES_GTK)
-  view_->AcceleratedCompositingActivated(activated);
+  if (view_)
+    view_->AcceleratedCompositingActivated(activated);
 #endif
 }
 
 #if defined(OS_MACOSX)
 
 void RenderWidgetHost::OnMsgGetScreenInfo(gfx::NativeViewId view,
                                           WebScreenInfo* results) {
   gfx::NativeView native_view = view_ ? view_->GetNativeView() : NULL;
   *results = WebScreenInfoFactory::screenInfo(native_view);
 }
@@ skipping 206 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).
     }
   }
 }