Move code around to fix build with system mesa.

ui/gl/generate_bindings.py

 #!/usr/bin/env python
 # 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.
 
 """code generator for GL/GLES extension wrangler."""
 
 import optparse
 import os
 import collections
@@ skipping 1134 matching lines @@
   'arguments':
       'Display* dpy, GLXDrawable drawable, int32* numerator, '
       'int32* denominator' },
 ]
 
 FUNCTION_SETS = [
   [GL_FUNCTIONS, 'gl', [
       'GL/glext.h',
       'GLES2/gl2ext.h',
       # Files below are Chromium-specific and shipped with Chromium sources.
+      'GL/glextchromium.h',
       'GLES2/gl2chromium.h',
       'GLES2/gl2extchromium.h'
   ], []],
   [OSMESA_FUNCTIONS, 'osmesa', [], []],
-  [EGL_FUNCTIONS, 'egl', ['EGL/eglext.h'],
+  [EGL_FUNCTIONS, 'egl', [
+      'EGL/eglext.h',
+      # Files below are Chromium-specific and shipped with Chromium sources.
+      'EGL/eglextchromium.h',
+    ],
     [
       'EGL_ANGLE_d3d_share_handle_client_buffer',
       'EGL_ANGLE_surface_d3d_texture_2d_share_handle',
     ],
   ],
   [WGL_FUNCTIONS, 'wgl', ['GL/wglext.h'], []],
   [GLX_FUNCTIONS, 'glx', ['GL/glx.h', 'GL/glxext.h'], []],
 ]
 
 def GenerateHeader(file, functions, set_name, used_extension_functions):
@@ skipping 416 matching lines @@
 
 def ParseExtensionFunctionsFromHeader(header_file):
   """Parse a C extension header file and return a map from extension names to
   a list of functions.
 
   Args:
     header_file: Line-iterable C header file.
   Returns:
     Map of extension name => functions.
   """
-  extension_start = re.compile(r'#define ([A-Z]+_[A-Z]+_[a-zA-Z]\w+) 1')
+  extension_start = re.compile(
+      r'#ifndef ((?:GL|EGL|WGL|GLX)_[A-Z]+_[a-zA-Z]\w+)')
   extension_function = re.compile(r'.+\s+([a-z]+\w+)\s*\(')
   typedef = re.compile(r'typedef .*')
   macro_start = re.compile(r'^#(if|ifdef|ifndef).*')
   macro_end = re.compile(r'^#endif.*')
   macro_depth = 0
   current_extension = None
   current_extension_depth = 0
   extensions = collections.defaultdict(lambda: [])
   for line in header_file:
     if macro_start.match(line):
@@ skipping 174 matching lines @@
     header_file.close()
 
   source_file = open(os.path.join(dir, 'gl_bindings_autogen_mock.cc'), 'wb')
   GenerateMockSource(source_file, GL_FUNCTIONS)
   source_file.close()
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))