Implement HiDPI support in Pepper dev interface

ppapi/proxy/ppb_graphics_2d_proxy.h

Index: ppapi/proxy/ppb_graphics_2d_proxy.h
diff --git a/ppapi/proxy/ppb_graphics_2d_proxy.h b/ppapi/proxy/ppb_graphics_2d_proxy.h
index f7afb64c431504f6baa42170d0928a2f4706f578..34e6aafa8dc7d820ea410afd784d79d1662f0c81 100644
--- a/ppapi/proxy/ppb_graphics_2d_proxy.h
+++ b/ppapi/proxy/ppb_graphics_2d_proxy.h
@@ -30,7 +30,8 @@ class PPB_Graphics2D_Proxy : public InterfaceProxy {
 
   static PP_Resource CreateProxyResource(PP_Instance instance,
                                          const PP_Size& size,
-                                         PP_Bool is_always_opaque);
+                                         PP_Bool is_always_opaque,
+                                         float scale_fctor);
 
   // InterfaceProxy implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
@@ -42,6 +43,7 @@ class PPB_Graphics2D_Proxy : public InterfaceProxy {
   void OnHostMsgCreate(PP_Instance instance,
                        const PP_Size& size,
                        PP_Bool is_always_opaque,
+                       float scale,
                        HostResource* result);
   void OnHostMsgPaintImageData(const HostResource& graphics_2d,
                                const HostResource& image_data,