Moved the logic of maintaining the current context to gles2 helper library.

ppapi/cpp/dev/graphics_3d_dev.h

 // Copyright (c) 2010 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 PPAPI_CPP_DEV_GRAPHICS_3D_DEV_H_
 #define PPAPI_CPP_DEV_GRAPHICS_3D_DEV_H_
 
 #include "ppapi/c/dev/ppb_graphics_3d_dev.h"
 #include "ppapi/c/dev/ppb_opengles_dev.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/resource.h"
 
 namespace pp {
 
 class Graphics3D_Dev : public Resource {
  public:
   static bool GetConfigs(int32_t* configs, int32_t config_size,
                          int32_t* num_config);
 
   static bool ChooseConfig(const int32_t* attrib_list, int32_t* configs,
                            int32_t config_size, int32_t* num_config);
 
   static bool GetConfigAttrib(int32_t config, int32_t attribute,
                               int32_t* value);
 
   static const char* QueryString(int32_t name);
 
   static void* GetProcAddress(const char* name);
 
-  static bool ResetCurrent();
-  static Graphics3D_Dev GetCurrentContext();
   static uint32_t GetError();
-  static const PPB_OpenGLES_Dev* GetImplementation();
+  static const PPB_OpenGLES2_Dev* GetImplementation();
 
   // Creates an is_null() Graphics3D object.
   Graphics3D_Dev() {}
 
   Graphics3D_Dev(const Instance& instance,
                  int32_t config,
                  int32_t share_context,
                  const int32_t* attrib_list);
 
-  bool MakeCurrent() const;
   bool SwapBuffers() const;
 
  protected:
   explicit Graphics3D_Dev(PP_Resource resource_id) : Resource(resource_id) {}
   static Graphics3D_Dev FromResource(PP_Resource resource_id);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_DEV_GRAPHICS_3D_DEV_H_