Inform webkit when PPAPI plugin contents are opaque.

webkit/plugins/ppapi/ppb_graphics_3d_impl.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 WEBKIT_PLUGINS_PPAPI_PPB_GRAPHICS_3D_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_GRAPHICS_3D_IMPL_H_
 
 #include "base/memory/weak_ptr.h"
 #include "ppapi/shared_impl/ppb_graphics_3d_shared.h"
 #include "ppapi/shared_impl/resource.h"
@@ skipping 28 matching lines @@
       int32_t put_offset,
       int32_t last_known_get) OVERRIDE;
 
   // Binds/unbinds the graphics of this context with the associated instance.
   // Returns true if binding/unbinding is successful.
   bool BindToInstance(bool bind);
 
   // Returns the id of texture that can be used by the compositor.
   unsigned int GetBackingTextureId();
 
+  // Returns true if the backing texture is always opaque.
+  bool IsOpaque();
+
   // Notifications about the view's progress painting.  See PluginInstance.
   // These messages are used to send Flush callbacks to the plugin.
   void ViewWillInitiatePaint();
   void ViewInitiatedPaint();
   void ViewFlushedPaint();
 
   PluginDelegate::PlatformContext3D* platform_context() {
     return platform_context_.get();
   }
 
@@ skipping 24 matching lines @@
   scoped_ptr<PluginDelegate::PlatformContext3D> platform_context_;
   base::WeakPtrFactory<PPB_Graphics3D_Impl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_Graphics3D_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_GRAPHICS_3D_IMPL_H_