Add Pepper support for several GL extensions

ppapi/shared_impl/ppb_opengles2_shared.h

Index: ppapi/shared_impl/ppb_opengles2_shared.h
diff --git a/ppapi/shared_impl/ppb_opengles2_shared.h b/ppapi/shared_impl/ppb_opengles2_shared.h
index 2b4c9f9110c5a9b0f21581c1b5f73023a30b1be4..3aae8f48c107912ecb31c297f4fe1d6391ba6ed1 100644
--- a/ppapi/shared_impl/ppb_opengles2_shared.h
+++ b/ppapi/shared_impl/ppb_opengles2_shared.h
@@ -13,6 +13,13 @@ namespace ppapi {
 class PPAPI_SHARED_EXPORT PPB_OpenGLES2_Shared {
  public:
   static const PPB_OpenGLES2* GetInterface();
+  static const PPB_OpenGLES2InstancedArrays* GetInstancedArraysInterface();
+  static const PPB_OpenGLES2FramebufferBlit* GetFramebufferBlitInterface();
+  static const PPB_OpenGLES2FramebufferMultisample*
+      GetFramebufferMultisampleInterface();
+  static const PPB_OpenGLES2ChromiumEnableFeature*
+      GetChromiumEnableFeatureInterface();
+  static const PPB_OpenGLES2ChromiumMapSub* GetChromiumMapSubInterface();
 };
 
 }  // namespace ppapi