Remove ANGLE_pack_reverse_row_order.

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

 #ifndef __gl2ext_h_
 #define __gl2ext_h_
 
 /* $Revision: 16619 $ on $Date:: 2012-01-18 10:00:14 -0800 #$ */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /*
@@ skipping 189 matching lines @@
 #define GL_READ_FRAMEBUFFER_BINDING_ANGLE                       0x8CAA
 #endif
 
 /* GL_ANGLE_framebuffer_multisample */
 #ifndef GL_ANGLE_framebuffer_multisample
 #define GL_RENDERBUFFER_SAMPLES_ANGLE                           0x8CAB
 #define GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_ANGLE             0x8D56
 #define GL_MAX_SAMPLES_ANGLE                                    0x8D57
 #endif
 
-/* GL_ANGLE_pack_reverse_row_order */
-#ifndef GL_ANGLE_pack_reverse_row_order
-#define GL_PACK_REVERSE_ROW_ORDER_ANGLE                         0x93A4
-#endif
-
 /* GL_ANGLE_texture_usage */
 #ifndef GL_ANGLE_texture_usage
 #define GL_TEXTURE_USAGE_ANGLE                                  0x93A2
 #define GL_FRAMEBUFFER_ATTACHMENT_ANGLE                         0x93A3
 #endif
 
 /* GL_ANGLE_instanced_arrays */
 #ifndef GL_ANGLE_instanced_arrays
 #define GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE                    0x88FE
 #endif
@@ skipping 1756 matching lines @@
 #define GL_CHROMIUM_command_buffer_query 1
 // TODO(gman): Get official numbers for these constants.
 #define GL_COMMANDS_ISSUED_CHROMIUM 0x84F2
 #endif
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* __gl2ext_h_ */