Rename the shared_impl resource files to give them more regular names.

ppapi/shared_impl/ppb_opengles2_shared.cc

 // 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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // DO NOT EDIT!
 
 #include "ppapi/shared_impl/ppb_opengles2_shared.h"
 
@@ skipping 878 matching lines @@
   &Viewport
 };
 
 }  // namespace
 
 const PPB_OpenGLES2* PPB_OpenGLES2_Shared::GetInterface() {
   return &ppb_opengles2;
 }
 
 }  // namespace ppapi