[Pepper GL] Use shared state to fix a memory leak in MapSub GL extension.

ppapi/proxy/ppapi_messages.h

Index: ppapi/proxy/ppapi_messages.h
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index 9afdcbc10e3ee7420eb35aad78ef56cc0b5b4461..f644461fe58fce454ba07254a0571ad8541ecf31 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -856,11 +856,12 @@ IPC_MESSAGE_ROUTED1(PpapiHostMsg_PPBCore_ReleaseResource,
                     ppapi::HostResource)
 
 // PPB_Graphics3D.
-IPC_SYNC_MESSAGE_ROUTED3_1(PpapiHostMsg_PPBGraphics3D_Create,
+IPC_SYNC_MESSAGE_ROUTED3_2(PpapiHostMsg_PPBGraphics3D_Create,
                            PP_Instance /* instance */,
                            ppapi::HostResource /* share_context */,
                            std::vector<int32_t> /* attrib_list */,
-                           ppapi::HostResource /* result */)
+                           ppapi::HostResource /* result */,
+                           ppapi::proxy::SerializedHandle /* shared_state */)
 IPC_SYNC_MESSAGE_ROUTED2_0(PpapiHostMsg_PPBGraphics3D_SetGetBuffer,
                            ppapi::HostResource /* context */,
                            int32 /* transfer_buffer_id */)