Fix presubmit_scheme_histograms.py and presubmit_bad_message_reasons.py

extensions/browser/PRESUBMIT.py

 # 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.
 
 """Chromium presubmit script for src/extensions/browser.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details on the presubmit API built into depot_tools.
 """
 
@@ skipping 18 matching lines @@
 def _RunHistogramValueCheckers(input_api, output_api):
   results = []
   histogram_paths = ('extensions/browser/extension_event_histogram_value.h',
                      'extensions/browser/extension_function_histogram_value.h')
   for path in histogram_paths:
     results += _CreateHistogramValueChecker(input_api, output_api, path).Run()
   return results
 
 def _RunHistogramChecks(input_api, output_api, histogram_name):
   try:
-    # Setup sys.path so that we can call histrogram code
+    # Setup sys.path so that we can call histograms code.
     import sys
     original_sys_path = sys.path
     sys.path = sys.path + [input_api.os_path.join(
       input_api.change.RepositoryRoot(),
       'tools', 'metrics', 'histograms')]
 
     import presubmit_bad_message_reasons
     return presubmit_bad_message_reasons.PrecheckBadMessage(input_api,
       output_api, histogram_name)
   except:
     return [output_api.PresubmitError('Could not verify histogram!')]
   finally:
     sys.path = original_sys_path
 
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results += _RunHistogramValueCheckers(input_api, output_api)
   results += _RunHistogramChecks(input_api, output_api,
     "BadMessageReasonExtensions")
   return results