Removing GL context rate limiting feature and related wrappers

ppapi/lib/gl/include/GLES2/gl2ext.h

Index: ppapi/lib/gl/include/GLES2/gl2ext.h
diff --git a/ppapi/lib/gl/include/GLES2/gl2ext.h b/ppapi/lib/gl/include/GLES2/gl2ext.h
index d690a9dd5c18c93a07cc6338edb7e81aa29a84b5..0ef4123de9a0194bed6bbe7f4186f37237c771c8 100644
--- a/ppapi/lib/gl/include/GLES2/gl2ext.h
+++ b/ppapi/lib/gl/include/GLES2/gl2ext.h
@@ -1784,25 +1784,6 @@ typedef void (GL_APIENTRYP PFNGLREQUESTEXTENSIONCHROMIUM) (const GLchar *extensi
 #endif
 #endif
 
-/* GL_CHROMIUM_rate_limit_offscreen_context */
-/*
- * This extension will block if the calling context has gotten more than two
- * glRateLimit calls ahead of the GPU process. This keeps the client in sync
- * with the GPU without having to call swapbuffers, which has potentially
- * undesirable side effects.
- */
-#ifndef GL_CHROMIUM_rate_limit_offscreen_context
-#define GL_CHROMIUM_rate_limit_offscreen_context 1
-#ifdef GL_GLEXT_PROTOTYPES
-#define glRateLimitOffscreenContextCHROMIUM  GLES2_GET_FUN(RateLimitOffscreenContextCHROMIUM)
-#if !defined(GLES2_USE_CPP_BINDINGS)
-GL_APICALL void GL_APIENTRY glRateLimitOffscreenContextCHROMIUM (void);
-#endif
-#else
-typedef void (GL_APIENTRYP PFNGLRATELIMITOFFSCREENCONTEXTCHROMIUM) ();
-#endif
-#endif
-
 /* GL_CHROMIUM_get_multiple */
 /*
  * This extension provides functions for quering multiple GL state with a single