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

content/browser/renderer_host/render_widget_host_view_aura.h

Index: content/browser/renderer_host/render_widget_host_view_aura.h
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 3c4814ed725a5e6e0df3af38534ee5d1f3722857..19c603035e81524fab473fc7a1e3d5054806b080 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -62,6 +62,7 @@ class RenderWidgetHostViewAura
   virtual gfx::NativeViewId GetNativeViewId() const OVERRIDE;
   virtual gfx::NativeViewAccessible GetNativeViewAccessible() OVERRIDE;
   virtual bool HasFocus() const OVERRIDE;
+  virtual bool HasSurface() const OVERRIDE;
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
   virtual bool IsShowing() OVERRIDE;