Revert 88452 (broke gpu_unittests) - Fix LUMANINCE_ALPHA issue

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
===================================================================
--- gpu/command_buffer/common/gles2_cmd_utils.cc	(revision 88456)
+++ gpu/command_buffer/common/gles2_cmd_utils.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 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.
 
@@ -323,7 +323,6 @@
     case GL_RGB:
        return 3;
     case GL_LUMINANCE_ALPHA:
-       return 2;
     case GL_RGBA:
     case GL_BGRA_EXT:
        return 4;