Linux: use generated shim headers for system mesa.

ui/gl/gl.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
 
   'targets': [
@@ skipping 100 matching lines @@
         '<(gl_binding_output_dir)/gl_interface_autogen_gl.h',
       ],
       # hard_dependency is necessary for this target because it has actions
       # that generate header files included by dependent targets. The header
       # files must be generated before the dependents are compiled. The usual
       # semantics are to allow the two targets to build concurrently.
       'hard_dependency': 1,
       'actions': [
         {
           'action_name': 'generate_gl_bindings',
+          'variables': {
+            'generator_path': 'generate_bindings.py',
+            'conditions': [
+              ['use_system_mesa==0', {
+                'header_paths': '../../third_party/mesa/MesaLib/include:../../third_party/khronos',
+              }, { # use_system_mesa==1
+                'header_paths': '/usr/include',
+              }],
+            ],
+          },
           'inputs': [
-            'generate_bindings.py',
-            '<(DEPTH)/third_party/khronos/GLES2/gl2ext.h',
-            '<(DEPTH)/third_party/khronos/EGL/eglext.h',
-            '<(DEPTH)/third_party/mesa/MesaLib/include/GL/glext.h',
-            '<(DEPTH)/third_party/mesa/MesaLib/include/GL/glx.h',
-            '<(DEPTH)/third_party/mesa/MesaLib/include/GL/glxext.h',
-            '<(DEPTH)/third_party/mesa/MesaLib/include/GL/wglext.h',
+            '<(generator_path)',
+            '<!@(python <(generator_path) --header-paths=<(header_paths) --inputs)',
           ],
           'outputs': [
             '<(gl_binding_output_dir)/gl_bindings_autogen_egl.cc',
             '<(gl_binding_output_dir)/gl_bindings_autogen_egl.h',
             '<(gl_binding_output_dir)/gl_bindings_api_autogen_egl.h',
             '<(gl_binding_output_dir)/gl_bindings_autogen_gl.cc',
             '<(gl_binding_output_dir)/gl_bindings_autogen_gl.h',
             '<(gl_binding_output_dir)/gl_bindings_api_autogen_gl.h',
             '<(gl_binding_output_dir)/gl_bindings_autogen_glx.cc',
             '<(gl_binding_output_dir)/gl_bindings_autogen_glx.h',
@@ skipping 11 matching lines @@
             '<(gl_binding_output_dir)/gl_interface_autogen_osmesa.h',
             '<(gl_binding_output_dir)/gl_interface_autogen_wgl.h',
             '<(gl_binding_output_dir)/gl_mock_autogen_egl.h',
             '<(gl_binding_output_dir)/gl_mock_autogen_gl.h',
             '<(gl_binding_output_dir)/gl_mock_autogen_glx.h',
             '<(gl_binding_output_dir)/gl_mock_autogen_osmesa.h',
             '<(gl_binding_output_dir)/gl_mock_autogen_wgl.h',
           ],
           'action': [
             'python',
-            'generate_bindings.py',
+            '<(generator_path)',
+            '--header-paths=<(header_paths)',
             '<(gl_binding_output_dir)',
           ],
         },
       ],
       'conditions': [
         ['OS != "mac"', {
           'sources': [
             'egl_util.cc',
             'egl_util.h',
             'gl_context_egl.cc',
@@ skipping 110 matching lines @@
         ],
       },
       'sources': [
         'gl_mock.h',
         'gl_mock.cc',
         '<(gl_binding_output_dir)/gl_mock_autogen_gl.h',
       ],
     },
   ],
 }