Add a little script for resurrecting pre-fork Blink files

Since Sky is checked directly into mojo and does not contain
Blink history, I knew of no easy way to resurrect Blink files.

In making the V8 debugger work, I had to bring back a ton
of files and thus wrote a script to help me do so.

Maybe others will find this useful.

R=ojan@chromium.org

Review URL: https://codereview.chromium.org/732193002

engine/src/flutter/tools/resurrect.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Knows how to pull down files from the version of Blink we forked from.
+
+import argparse
+import requests
+import os
+import sys
+
+FORK_VERSION = "086acdd04cbe6fcb89b2fc6bd438fb8819a26776"
+
+parser = argparse.ArgumentParser("Tool for resurrecting pre-fork Blink files.")
+parser.add_argument("path", help="Path from Blink's Source root to the file."
+    "e.g. core/dom/ExecutionContextTask.h")
+args = parser.parse_args()
+
+BASE_URL = "http://blink.lc/blink/plain/Source/%s?id=%s"
+url = BASE_URL % (args.path, FORK_VERSION)
+response = requests.get(url)
+if response.status_code != 200:
+    print "Load failure: %s" % url
+    sys.exit(0)
+contents = response.text
+
+file_name = os.path.basename(args.path)
+
+if os.path.exists(file_name):
+    print "%s exists, do you want to overwrite [y/N]?" % file_name
+    if raw_input().lower() not in ('y', 'yes'):
+        print "Aborting."
+        sys.exit(1)
+
+with open(file_name, "w+") as output:
+    output.write(contents)
+    print "Wrote %s" % file_name