Pull Chromium dependencies to Pipa checkout via DEPS and GITDEPS.

GITDEPS

+# Copyright 2015 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# This file is read by gitdeps.py to allow loading subsections of git repos
+# through sparse checkouts.
+
+vars = {
+  "chrome_revision": "a691a7278a6f58da832b8818d2d00afa0687cd0d",

[ftirelo, 2017/02/15 18:02:16]

This will be used for the standalone version, right? In that case, would it make
sense to pull chromium at HEAD instead? In case we need to update the cleaner
code, we pull deps there.

[veranika, 2017/02/15 20:47:12]

Doing so will require some changes in the gitdeps.py script. I would prefer this
commit to contain only copy of the original script, so I'll send another CL for
doing so.

+  "gyp_revision": "bac4680ec9a5c55ab692490b6732999648ecf1e9",
+  "chrome_base_git": "https://chromium.googlesource.com/",
+}
+
+deps = {
+  "":(
+    Var("chrome_base_git") + "chromium/src",
+    [
+      # Chrome base and other top-level dependencies.
+      "base",
+      "build",
+      "testing",
+      "tools",
+
+      # third_party dependencies.
+      "third_party/protobuf",
+    ],
+    Var("chrome_revision")
+  ),
+  "tools/gyp":
+    (Var("chrome_base_git") + "external/gyp/",
+    [],
+    Var("gyp_revision")),
+}