todo use generate_shim_headers script

--- chromium-browser-24.0.1312.45/src/third_party/libXNVCtrl/libXNVCtrl.gyp	2013-01-04 00:45:35.620067292 +0200
+++ chromium-browser-25.0.1364.29/src/third_party/libXNVCtrl/libXNVCtrl.gyp	2013-01-12 16:17:25.440747088 +0200
@@ -5,14 +5,55 @@
 {
-  'targets': [
-    {
-      'target_name': 'libXNVCtrl',
-      'type': 'static_library',
-      'sources': [
-        'NVCtrl.c',
-        'NVCtrl.h',
-        'NVCtrlLib.h',
-        'nv_control.h',
+  'variables': {
+    'use_system_libxnvctrl%': 0,
+  },
+  'conditions': [
+    ['use_system_libxnvctrl==0', {
+      'targets': [
+        {
+          'target_name': 'libXNVCtrl',
+          'type': 'static_library',
+          'sources': [
+            'NVCtrl.c',
+            'NVCtrl.h',
+            'NVCtrlLib.h',
+            'nv_control.h',
+          ],
+        },
       ],
-    },
-  ],
+    }, { # use_system_libxnvctrl==1
+      'conditions': [
+        ['sysroot!=""', {
+          'variables': {
+            'pkg-config': '../../build/linux/pkg-config-wrapper "<(sysroot)" "<(target_arch)"',
+          },
+        }, {
+          'variables': {
+            'pkg-config': 'pkg-config'
+          },
+        }],
+      ],
+      'targets': [
+        {
+          'target_name': 'libXNVCtrl',
+          'type': 'none',
+          'direct_dependent_settings': {
+            'cflags': [
+                '<!@(<(pkg-config) --cflags libXNVCtrl)',
+            ],
+            'defines': [
+                'USE_SYSTEM_LIBXNVCTRL',
+            ],
+          },
+          'link_settings': {
+            'ldflags': [
+              '<!@(<(pkg-config) --libs-only-L --libs-only-other libXNVCtrl)',
+            ],
+            'libraries': [
+              '<!@(<(pkg-config) --libs-only-l libXNVCtrl)',
+            ],
+          },
+        }
+      ],
+    }],
+  ]
 }
--- chromium-browser-25.0.1364.29/src/content/gpu/gpu_info_collector_linux.cc	2013-01-12 16:11:48.998635662 +0200
+++ chromium-browser-25.0.1364.29/src/content/gpu/gpu_info_collector_linux.cc	2013-01-12 16:29:12.273316708 +0200
@@ -18,8 +18,7 @@
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
 #include "library_loaders/libpci.h"
-#include "third_party/libXNVCtrl/NVCtrl.h"
-#include "third_party/libXNVCtrl/NVCtrlLib.h"
+#include "third_party/libXNVCtrl/libXNVCtrl.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_implementation.h"
--- /dev/null	2007-02-13 18:29:53.000000000 +0200
+++ hromium-browser-25.0.1364.29/src/third_party/libXNVCtrl/libXNVCtrl.h	2013-01-12 16:27:55.676465329 +0200
@@ -0,0 +1,17 @@
+// Copyright (c) 2013 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.
+
+// This is a shim header to include the right opus header.
+// Use this instead of referencing the opus header directly.
+
+#if !defined(THIRD_PARTY_LIBXNVCTRL_LIBXNVCTRL_H)
+#define THIRD_PARTY_LIBXNVCTRL_LIBXNVCTRL_H
+#if defined(USE_SYSTEM_LIBXNVCTRL)
+#include <NVCtrl.h>
+#include <NVCtrlLib.h>
+#else
+#include "third_party/libXNVCtrl/NVCtrl.h"
+#include "third_party/libXNVCtrl/NVCtrlLib.h"
+#endif
+#endif