Cleanup: Presubmit API is built into depot_tools.

tools/valgrind/drmemory/PRESUBMIT.py

 # Copyright (c) 2012 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.
 """
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
-for more details on the presubmit API built into gcl.
+for more details on the presubmit API built into depot_tools.
 """
 
 
 def CheckChange(input_api, output_api):
   """Checks the DrMemory suppression files for bad suppressions."""
 
   # TODO(timurrrr): find out how to do relative imports
   # and remove this ugly hack. Also, the CheckChange function won't be needed.
   tools_vg_path = input_api.os_path.join(input_api.PresubmitLocalPath(), '..')
   import sys
@@ skipping 13 matching lines @@
 def CheckChangeOnCommit(input_api, output_api):
   return CheckChange(input_api, output_api)
 
 
 def GetPreferredTryMasters(project, change):
   return {
     'tryserver.chromium.win': {
       'win_drmemory': set(['defaulttests']),
     }
   }