Allow for building content_shell from within WebKit

content/content_common.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': [
     '../base/base.gyp:base',
     '../build/temp_gyp/googleurl.gyp:googleurl',
     '../gpu/gpu.gyp:gles2_implementation',
     '../gpu/gpu.gyp:gpu_ipc',
     '../ipc/ipc.gyp:ipc',
     '../media/media.gyp:media',
     '../net/net.gyp:net',
     '../skia/skia.gyp:skia',
     '../third_party/icu/icu.gyp:icuuc',
     '../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/gl/gl.gyp:gl',
     '../ui/ui.gyp:ui',
     '../webkit/support/webkit_support.gyp:appcache',
     '../webkit/support/webkit_support.gyp:blob',
     '../webkit/support/webkit_support.gyp:database',
     '../webkit/support/webkit_support.gyp:fileapi',
   ],
   'include_dirs': [
     '..',
   ],
@@ skipping 423 matching lines @@
         '../build/extract_from_cab.py',
         '..\\third_party\\directxsdk\\files\\Redist\\<(input)',
         '<(output)',
         '<(PRODUCT_DIR)',
         ],
       },
      ]
     }]
   ],
 }