Fix Blink roll script to handle git revisions.

tools/safely-roll-blink.py

Index: tools/safely-roll-blink.py
diff --git a/tools/safely-roll-blink.py b/tools/safely-roll-blink.py
index 581aecd5c6bb1ddfd3c2514f7c8130d06d502412..af7c12df1e94e09e8ac0cf9838ce606537226947 100755
--- a/tools/safely-roll-blink.py
+++ b/tools/safely-roll-blink.py
@@ -30,8 +30,8 @@ def process_deps(path, new_rev, is_dry_run):
   A bit hacky, could it be made better?
   """
   content = open(path).read()
-  old_line = r'(\s+)"webkit_revision": "(\d+)",'
-  new_line = r'\1"webkit_revision": "%d",' % new_rev
+  old_line = r"(\s+)'webkit_revision': '([a-f0-9]{40})',"
+  new_line = r"\1'webkit_revision': '%s'," % new_rev
   new_content = re.sub(old_line, new_line, content, 1)
   old_rev = re.search(old_line, content).group(2)
   if not old_rev or new_content == content:
@@ -42,9 +42,19 @@ def process_deps(path, new_rev, is_dry_run):
   return old_rev
 
 
+def get_svn_rev_from_git_rev(git_rev):
+  """Return the svn revision associated with the Blink git revision."""
+
+  os.chdir("third_party/WebKit/")
+  log = subprocess2.check_output(['git', 'log', git_rev, '-n', '1'])
+  rev_line = r"\s+git-svn-id: svn://svn.chromium.org/blink/trunk@(\d+)"
+  os.chdir("../..")
+
+  return int(re.search(rev_line, log).group(1))
+
 def main():
   tool_dir = os.path.dirname(os.path.abspath(__file__))
-  parser = optparse.OptionParser(usage='%prog [options] <new blink rev>')
+  parser = optparse.OptionParser(usage='%prog [options] <new blink git rev>')
   parser.add_option('-v', '--verbose', action='count', default=0)
   parser.add_option('--dry-run', action='store_true')
   parser.add_option('--commit', action='store_true', default=True,
@@ -72,7 +82,7 @@ def main():
   root_dir = os.path.dirname(tool_dir)
   os.chdir(root_dir)
 
-  new_rev = int(args[0])
+  new_git_rev = args[0]
 
   # Silence the editor.
   os.environ['EDITOR'] = 'true'
@@ -87,9 +97,13 @@ def main():
         ['git', 'checkout', '-b', 'blink_roll', options.upstream])
 
   try:
-    old_rev = int(process_deps(os.path.join(root_dir, 'DEPS'), new_rev,
-                               options.dry_run))
-    print 'Blink roll %s:%s' % (old_rev, new_rev)
+    old_git_rev = process_deps(os.path.join(root_dir, 'DEPS'), new_git_rev,
+                               options.dry_run)
+
+    new_svn_rev = get_svn_rev_from_git_rev(new_git_rev)
+    old_svn_rev = get_svn_rev_from_git_rev(old_git_rev)
+
+    print 'Blink roll %s:%s' % (old_svn_rev, new_svn_rev)
 
     review_field = 'TBR' if options.commit else 'R'
     commit_msg = ('Blink roll %s:%s\n'
@@ -97,8 +111,8 @@ def main():
                  'http://build.chromium.org/f/chromium/perf/dashboard/ui/'
                  'changelog_blink.html?url=/trunk&range=%s:%s&mode=html'
                  '\n'
-                 '%s=%s\n' % (old_rev, new_rev,
-                              old_rev+1, new_rev,
+                 '%s=%s\n' % (old_svn_rev, new_svn_rev,
+                              old_svn_rev+1, new_svn_rev,
                               review_field,
                               options.reviewers))