Add a WebCore directory to the python path so we can use pymod_do_main

in Webore.gyp.

In https://bugs.webkit.org/show_bug.cgi?id=106604 , I'm adding a script
for generating idl dependencies. To make it run faster, I'm using
pymod_do_main.

BUG=None

Review URL: https://codereview.chromium.org/11866008

git-svn-id: http://src.chromium.org/svn/trunk/src/build@176437 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

gyp_chromium

@@ -25,6 +25,8 @@ sys.path.insert(1, os.path.join(chrome_src, 'tools', 'generate_shim_headers'))
 sys.path.insert(1, os.path.join(chrome_src, 'tools', 'grit'))
 sys.path.insert(1, os.path.join(chrome_src, 'chrome', 'tools', 'build'))
 sys.path.insert(1, os.path.join(chrome_src, 'native_client', 'build'))
+sys.path.insert(1, os.path.join(chrome_src, 'third_party', 'WebKit',
+    'Source', 'WebCore', 'WebCore.gyp', 'scripts'))
 
 
 # On Windows, Psyco shortens warm runs of build/gyp_chromium by about