Allow for building content_shell from within WebKit

content/content_renderer.gypi

 # 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.
 
 {
   'dependencies': [
     '../jingle/jingle.gyp:jingle_glue',
     '../net/net.gyp:net',
     '../ppapi/ppapi_internal.gyp:ppapi_proxy',
     '../ppapi/ppapi_internal.gyp:ppapi_shared',
     '../skia/skia.gyp:skia',
     '../third_party/ffmpeg/ffmpeg.gyp:ffmpeg',
     '../third_party/icu/icu.gyp:icuuc',
     '../third_party/icu/icu.gyp:icui18n',
     '../third_party/libjingle/libjingle.gyp:libjingle',
     '../third_party/libjingle/libjingle.gyp:libjingle_p2p',
     '../third_party/npapi/npapi.gyp:npapi',
-    '../third_party/WebKit/Source/WebKit/chromium/WebKit.gyp:webkit',
+    '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:webkit',
     '../ui/surface/surface.gyp:surface',
     '../v8/tools/gyp/v8.gyp:v8',
     '../webkit/support/webkit_support.gyp:webkit_media',
     '../webkit/support/webkit_support.gyp:webkit_gpu',
   ],
   'include_dirs': [
     '..',
   ],
   'sources': [
     'public/renderer/content_renderer_client.h',
@@ skipping 265 matching lines @@
     }, {
       'sources!': [
         'renderer/java/java_bridge_channel.cc',
         'renderer/java/java_bridge_channel.h',
         'renderer/java/java_bridge_dispatcher.cc',
         'renderer/java/java_bridge_dispatcher.h',
       ],
     }],
   ],
 }