Revert r118525 / Re-land r118240 - the build failure was a flake.

gpu/command_buffer/client/gles2_c_lib.cc

Index: gpu/command_buffer/client/gles2_c_lib.cc
diff --git a/gpu/command_buffer/client/gles2_c_lib.cc b/gpu/command_buffer/client/gles2_c_lib.cc
index 4e853c2d0e8711eec9ac43e412c7e35e94f170fc..0bed5f8f40180e727dde69a364322875bb0ea81d 100644
--- a/gpu/command_buffer/client/gles2_c_lib.cc
+++ b/gpu/command_buffer/client/gles2_c_lib.cc
@@ -1,12 +1,17 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
-// These functions emluate GLES2 over command buffers for C.
+// These functions emulate GLES2 over command buffers for C.
 
 #include <assert.h>
 #include "../client/gles2_lib.h"
 
+#ifndef GL_GLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+#endif
+#include <GLES2/gl2ext.h>
+
 extern "C" {
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file