Update dartium DEPS to use co19 from github.

tools/deps/dartium.deps/DEPS

 import gclient_utils
 import os
 
 path = gclient_utils.FindGclientRoot(os.getcwd())
 execfile(os.path.join(path, 'src', 'dart', 'tools', 'deps', 'dartium.deps', 'DEPS.chromium')) # Include proper Chromium DEPS.
 
 # Now we need to override some settings and add some new ones.
 
 vars.update({
   "chromium_url": "http://src.chromium.org/svn",
@@ skipping 35 matching lines @@
   "stack_trace_tag": "@1.2.1",
   "string_scanner_rev": "@3e7617d6f74ba382e9b6130b1cc12091d89a9bc5",
   "test_tag": "@0.12.1",
   "unittest_tag": "@0.11.6",
   "utf_rev": "@1f55027068759e2d52f2c12de6a57cce5f3c5ee6",
   "watcher_tag": "@0.9.5",
   "yaml_rev": "@563a5ffd4a800a2897b8f4dd6b19f2a370df2f2b",
   "zlib_rev": "@c3d0a6190f2f8c924a05ab6cc97b8f975bddd33f",
   "web_components_rev": "@0e636b534d9b12c9e96f841e6679398e91a986ec",
 
-  "co19_rev": "@801",
+  "co19_rev": "@f95f109fea67127a220958794ef5200a63cb454c",

[terry, 2015/08/14 16:07:48]

The SHA1 should be 34010003cd3e74085084c92816247b53cc8be491 however, I can do
that after your CL.  The hash your using is where I started the co91 integration
branch the above hash are my changes.

   "fake_async_rev": "@38614",
 })
 
 def massage_deps(deps):
   for key, value in deps.items():
     if value is None: continue
 
     if value.startswith('/trunk'):
       deps[key] = Var("chromium_url") + value
       continue
@@ skipping 103 matching lines @@
       "https://github.com/dart-lang/web-components.git" +
       Var("web_components_rev"),
 
   "src/dart/third_party/WebCore":
     "http://dart.googlecode.com/svn/third_party/WebCore",
 
   "src/dart/third_party/pkg/fake_async":
     "http://dart.googlecode.com/svn/third_party/fake_async" +
     Var("fake_async_rev"),
 
-  "src/dart/tests/co19/src": ((Var("googlecode_url") % "co19") +
-    "/trunk/co19/tests/co19/src" + Var("co19_rev")),
+  "src/dart/tests/co19/src":
+      "https://github.com/dart-lang/co19.git" + Var("co19_rev"),
 
   "src/dart/third_party/zlib":
       Var("chromium_git") + "/chromium/src/third_party/zlib.git" +
       Var("zlib_rev"),
 })
 
 deps_os['win'].update({
   "src/chrome/tools/test/reference_build/chrome_win": None
 })
 deps_os['mac'].update({
@@ skipping 34 matching lines @@
     "download_from_google_storage",
     "--no_auth",
     "--no_resume",
     "--bucket",
     "dart-dependencies",
     "-d",
     "-r",
     "src/dart/tools/testing/bin",
   ],
 })