PPAPI: Fix interface functions that take PP_CompletionCallbacks, but don't

webkit/plugins/ppapi/ppb_layer_compositor_impl.h

 // Copyright (c) 2011 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_LAYER_COMPOSITOR_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_LAYER_COMPOSITOR_IMPL_H_
 
 #include "ppapi/c/dev/ppb_layer_compositor_dev.h"
 #include "webkit/plugins/ppapi/resource.h"
 
@@ skipping 14 matching lines @@
 
   // Resource override.
   virtual PPB_LayerCompositor_Impl* AsPPB_LayerCompositor_Impl();
 
   PP_Bool AddLayer(PP_Resource layer);
   void RemoveLayer(PP_Resource layer);
   void SetZIndex(PP_Resource layer, int32_t index);
   void SetRect(PP_Resource layer, const struct PP_Rect* rect);
   void SetDisplay(PP_Resource layer, PP_Bool is_displayed);
   void MarkAsDirty(PP_Resource layer);
-  PP_Bool SwapBuffers(struct PP_CompletionCallback callback);
+  int32_t SwapBuffers(struct PP_CompletionCallback callback);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PPB_LayerCompositor_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_LAYER_COMPOSITOR_IMPL_H_