[Findit] Fetch DEPS from buildspec/ instead of trunk for chrome official builds.

appengine/findit/crash/callstack_filters.py

+# Copyright 2016 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.
+
+import re
+
+
+def FilterFramesBeforeSignature(callstack, signature):
+  """Filter all the stack frames before the signature frame.
+
+  Note: The callstack is filtered in place.
+  """
+  if not signature:
+    return
+
+  signature_frame_index = 0
+  # Filter out the types of signature, for example [Out of Memory].
+  signature = re.sub('[[][^]]*[]]\s*', '', signature)
+
+  for index, frame in enumerate(callstack):
+    if signature in frame.function:
+      signature_frame_index = index
+
+  callstack[:] = callstack[signature_frame_index:]