Update bisect script to handle deleted .DEPS.git from chromium source

tools/auto_bisect/bisect_utils.py

Index: tools/auto_bisect/bisect_utils.py
diff --git a/tools/auto_bisect/bisect_utils.py b/tools/auto_bisect/bisect_utils.py
index 56a4cd8519c53766fb4aeaa09fab04dc3b948b1d..a0017012d352a94ad7ea971ac5d85c8255021335 100644
--- a/tools/auto_bisect/bisect_utils.py
+++ b/tools/auto_bisect/bisect_utils.py
@@ -285,18 +285,34 @@ def RunGClientAndCreateConfig(opts, custom_deps=None, cwd=None):
   return return_code
 
 
-def IsDepsFileBlink():
+def IsDepsFileBlink(git_revision=''):
   """Reads .DEPS.git and returns whether or not we're using blink.
 
+  Args:
+    git_revision: A git hash revision of chromium.
   Returns:
     True if blink, false if webkit.
   """
-  locals = {
+  git_cmd = ['cat-file', 'blob', '%s:%s' %(git_revision, FILE_DEPS_GIT)]
+  search_str = 'blink.git'
+  search_key = 'webkit_url'
+  (out_put, ret_val) = RunGit(git_cmd)
+  if ret_val:
+    search_str = 'blink'
+    search_key = 'webkit_trunk'
+    git_cmd = ['cat-file', 'blob', '%s:%s' %(git_revision, 'FILE_DEPS')]
+    (out_put, ret_val) = RunGit(git_cmd)
+    if ret_val:
+      print 'Error processing DEPS or .DEPS.git'
+      return False
+  locals =  {
       'Var': lambda _: locals["vars"][_],
       'From': lambda *args: None
   }
-  execfile(FILE_DEPS_GIT, {}, locals)
-  return 'blink.git' in locals['vars']['webkit_url']
+
+  exec out_put in  {}, locals
+
+  return search_str in locals['vars'][search_key]
 
 
 def OnAccessError(func, path, _):