Update 'libyuv' to reference new canonical repo.

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 216 matching lines @@
   'src/third_party/webrtc':
     Var('chromium_git') + '/external/webrtc/trunk/webrtc.git' + '@' + '95797c571819af56d1c15beebc503c57e8ca1df4', # commit position 9390
 
   'src/third_party/openmax_dl':
     Var('chromium_git') + '/external/webrtc/deps/third_party/openmax.git' + '@' +  Var('openmax_dl_revision'),
 
   'src/third_party/jsoncpp/source':
     Var('chromium_git') + '/external/github.com/open-source-parsers/jsoncpp.git' + '@' + 'f572e8e42e22cfcf5ab0aea26574f408943edfa4', # from svn 248
 
   'src/third_party/libyuv':
-    Var('chromium_git') + '/external/libyuv.git' + '@' + '632c50f29cdacb8c5872ce9938444b676b4a0c81', # from svn revision 1407
+    Var('chromium_git') + '/libyuv/libyuv.git' + '@' + '632c50f29cdacb8c5872ce9938444b676b4a0c81', # from svn revision 1407
 
   'src/third_party/smhasher/src':
     Var('chromium_git') + '/external/smhasher.git' + '@' + 'e87738e57558e0ec472b2fc3a643b838e5b6e88f',
 
   'src/third_party/libaddressinput/src':
     Var('chromium_git') + '/external/libaddressinput.git' + '@' + '61f63da7ae6fa469138d60dec5d6bbecc6ab43d6',
 
   # These are all at libphonenumber r728.
   'src/third_party/libphonenumber/src/phonenumbers':
     Var('chromium_git') + '/external/libphonenumber/cpp/src/phonenumbers.git' + '@' + '0d6e3e50e17c94262ad1ca3b7d52b11223084bca',
@@ skipping 533 matching lines @@
     # corresponding .py files have already been deleted.
     'name': 'remove_stale_pyc_files',
     'pattern': 'src/tools/.*\\.py',
     'action': [
         'python',
         'src/tools/remove_stale_pyc_files.py',
         'src/tools',
     ],
   },
 ]