Change a few github repo dependencies to use the GOB mirror

DEPS

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 vars = {
   # The dart_root is the root of our sdk checkout. This is normally
   # simply sdk, but if using special gclient specs it can be different.
   "dart_root": "sdk",
 
   # The svn location to pull out dependencies from
@@ skipping 101 matching lines @@
   "barback-0.14.1_rev": "@38525",
   "source_maps-0.9.4_rev": "@38524",
 }
 
 deps = {
   # Stuff needed for GYP to run.
   Var("dart_root") + "/third_party/gyp":
       (Var("googlecode_url") % "gyp") + "/trunk" + Var("gyp_rev"),
 
   Var("dart_root") + "/tests/co19/src":
-      "https://github.com/dart-lang/co19.git" + Var("co19_rev"),
+      (Var("github_mirror") % "co19") + Var("co19_rev"),
 
   Var("dart_root") + "/third_party/nss":
       Var("chromium_git") + "/chromium/deps/nss.git" + Var("nss_rev"),
 
   Var("dart_root") + "/third_party/sqlite":
       Var("chromium_git") + "/chromium/src/third_party/sqlite.git" +
       Var("sqlite_rev"),
 
   Var("dart_root") + "/third_party/zlib":
       Var("chromium_git") + "/chromium/src/third_party/zlib.git" +
@@ skipping 43 matching lines @@
 
   Var("dart_root") + "/third_party/pkg/analyzer_cli":
       (Var("github_mirror") % "analyzer_cli") + Var("analyzer_cli_rev"),
   Var("dart_root") + "/third_party/pkg/args":
       (Var("github_mirror") % "args") + Var("args_tag"),
   Var("dart_root") + "/third_party/pkg/async_await":
       (Var("github_mirror") % "async_await") + Var("async_await_rev"),
   Var("dart_root") + "/third_party/pkg/barback":
       (Var("github_mirror") % "barback") + Var("barback_rev"),
   Var("dart_root") + "/third_party/pkg/charcode":
-      "https://github.com/dart-lang/charcode.git" + Var("charcode_tag"),
+      (Var("github_mirror") % "charcode") + Var("charcode_tag"),
   Var("dart_root") + "/third_party/pkg/cli_util":
-      "https://github.com/dart-lang/cli_util.git" + Var("cli_util_tag"),
+      (Var("github_mirror") % "cli_util") + Var("cli_util_tag"),
   Var("dart_root") + "/third_party/pkg/collection":
       (Var("github_mirror") % "collection") + Var("collection_rev"),
   Var("dart_root") + "/third_party/pkg/crypto":
       (Var("github_mirror") % "crypto") + Var("crypto_rev"),
   Var("dart_root") + "/third_party/pkg/csslib":
       (Var("github_mirror") % "csslib") + Var("csslib_tag"),
   Var("dart_root") + "/third_party/pkg_tested/dart_style":
       (Var("github_mirror") % "dart_style") + Var("dart_style_tag"),
   Var("dart_root") + "/third_party/pkg/glob":
       (Var("github_mirror") % "glob") + Var("glob_rev"),
@@ skipping 11 matching lines @@
       Var("http_throttle_rev"),
   Var("dart_root") + "/third_party/pkg/intl":
       (Var("github_mirror") % "intl") + Var("intl_rev"),
   Var("dart_root") + "/third_party/pkg/json_rpc_2":
       (Var("github_mirror") % "json_rpc_2") + Var("json_rpc_2_rev"),
   Var("dart_root") + "/third_party/pkg/linter":
       (Var("github_mirror") % "linter") + Var("linter_tag"),
   Var("dart_root") + "/third_party/pkg/logging":
       (Var("github_mirror") % "logging") + Var("logging_rev"),
   Var("dart_root") + "/third_party/pkg/markdown":
-      "https://github.com/dpeek/dart-markdown.git" + Var("markdown_rev"),
+      "https://chromium.googlesource.com/external/github.com" +
+      "/dpeek/dart-markdown.git" + Var("markdown_rev"),
   Var("dart_root") + "/third_party/pkg/matcher":
       (Var("github_mirror") % "matcher") + Var("matcher_tag"),
   Var("dart_root") + "/third_party/pkg/metatest":
       (Var("github_mirror") % "metatest") + Var("metatest_rev"),
   Var("dart_root") + "/third_party/pkg/mime":
       (Var("github_mirror") % "mime") + Var("mime_rev"),
   Var("dart_root") + "/third_party/pkg/oauth2":
       (Var("github_mirror") % "oauth2") + Var("oauth2_rev"),
   Var("dart_root") + "/third_party/pkg/observe":
       (Var("github_mirror") % "observe") + Var("observe_rev"),
@@ skipping 42 matching lines @@
   Var("dart_root") + "/third_party/pkg/usage":
       (Var("github_mirror") % "usage") + Var("usage_rev"),
   Var("dart_root") + "/third_party/pkg/utf":
       (Var("github_mirror") % "utf") + Var("utf_rev"),
   Var("dart_root") + "/third_party/pkg/watcher":
       (Var("github_mirror") % "watcher") + Var("watcher_tag"),
   Var("dart_root") + "/third_party/pkg/web_components":
       (Var("github_mirror") % "web-components") +
       Var("web_components_rev"),
   Var("dart_root") + "/third_party/pkg/when":
-      "https://github.com/dart-lang/when.git" + Var("when_tag"),
+      (Var("github_mirror") % "when") + Var("when_tag"),
   Var("dart_root") + "/third_party/pkg/which":
-      "https://github.com/dart-lang/which.git"+ Var("which_tag"),
+      (Var("github_mirror") % "which") + Var("which_tag"),
   Var("dart_root") + "/third_party/pkg/yaml":
       (Var("github_mirror") % "yaml") + Var("yaml_rev"),
 
   # These specific versions of barback and source_maps are used for testing and
   # should be pulled from bleeding_edge even on channels.
   Var("dart_root") + "/third_party/pkg/barback-0.13.0":
       Var("bleeding_edge") + "/dart/pkg/barback" + Var("barback-0.13.0_rev"),
   Var("dart_root") + "/third_party/pkg/barback-0.14.0+3":
       Var("bleeding_edge") + "/dart/pkg/barback" + Var("barback-0.14.0_rev"),
   Var("dart_root") + "/third_party/pkg/barback-0.14.1+4":
@@ skipping 38 matching lines @@
       '--no_auth',
       '--no_resume',
       '--bucket',
       'dart-dependencies',
       '-d',
       '-r',
       Var('dart_root') + '/tools/testing/bin',
     ],
   },
 ]