Prevent browser thumbnailer from trying to read from frontbuffer (surface texture) when none exists.

content/public/browser/render_widget_host_view.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 #pragma once
 
 #if defined(TOOLKIT_GTK)
 #include <gdk/gdk.h>
@@ skipping 64 matching lines @@
   // Retrieves the native view used to contain plugins and identify the
   // renderer in IPC messages.
   virtual gfx::NativeView GetNativeView() const = 0;
   virtual gfx::NativeViewId GetNativeViewId() const = 0;
   virtual gfx::NativeViewAccessible GetNativeViewAccessible() = 0;
 
   // Set focus to the associated View component.
   virtual void Focus() = 0;
   // Returns true if the View currently has the focus.
   virtual bool HasFocus() const = 0;
+  // Returns true is the current display surface is available.
+  virtual bool HasSurface() const = 0;

[mmocny, 2012/05/03 19:46:08]

This name is not nearly descriptive enough, but I needed to start with
something.  Suggestions welcome.

[mazda, 2012/05/03 20:19:33]

This is also confusing because there is similar function,
RenderWidgetHostViewPort::HasAcceleratedSurface.

HasCopyableSurface or something?

[mazda, 2012/05/04 22:20:32]

IsSurfaceAvailableForCopy in your latest patch looks good.

 
   // Shows/hides the view.  These must always be called together in pairs.
   // It is not legal to call Hide() multiple times in a row.
   virtual void Show() = 0;
   virtual void Hide() = 0;
 
   // Whether the view is showing.
   virtual bool IsShowing() = 0;
 
   // Retrieve the bounds of the View, in screen coordinates.
@@ skipping 47 matching lines @@
   // Return value indicates whether the mouse is locked successfully or not.
   virtual bool LockMouse() = 0;
   virtual void UnlockMouse() = 0;
   // Returns true if the mouse pointer is currently locked.
   virtual bool IsMouseLocked() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_