Change extensions enum presubmit checks to run on upload only

extensions/browser/PRESUBMIT.py

Index: extensions/browser/PRESUBMIT.py
diff --git a/extensions/browser/PRESUBMIT.py b/extensions/browser/PRESUBMIT.py
index a11b26171977fc6160e84c791f715ca6189f012a..15f8d932fc59b0197e39da7ec592f54336541cee 100644
--- a/extensions/browser/PRESUBMIT.py
+++ b/extensions/browser/PRESUBMIT.py
@@ -8,7 +8,36 @@ See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details on the presubmit API built into depot_tools.
 """
 
+import sys
+
+def _CreateHistogramValueChecker(input_api, output_api, path):
+  original_sys_path = sys.path
+
+  try:
+    sys.path.append(input_api.os_path.join(
+        input_api.PresubmitLocalPath(), '..', '..', 'tools',
+        'strict_enum_value_checker'))
+    from strict_enum_value_checker import StrictEnumValueChecker
+  finally:
+    sys.path = original_sys_path
+
+  return StrictEnumValueChecker(input_api, output_api,
+      start_marker='enum HistogramValue {', end_marker='  // Last entry:',
+      path=path)
+
+
+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 CheckChangeOnUpload(input_api, output_api):
   results = []
+  results += _RunHistogramValueCheckers(input_api, output_api)
   results += input_api.canned_checks.CheckPatchFormatted(input_api, output_api)
   return results
+