Add presubmit scripts to check histograms.xml if bad_message.h changes.

chrome/browser/PRESUBMIT.py

Index: chrome/browser/PRESUBMIT.py
diff --git a/chrome/browser/PRESUBMIT.py b/chrome/browser/PRESUBMIT.py
index 0dbbdae8a50666555dc6ce47b35e04ad60f4936b..0350a0624b30978bfd71b8b700d672338bc64f98 100644
--- a/chrome/browser/PRESUBMIT.py
+++ b/chrome/browser/PRESUBMIT.py
@@ -20,6 +20,23 @@ def CheckChangeOnUpload(input_api, output_api):
 def CheckChangeOnCommit(input_api, output_api):
   return _CommonChecks(input_api, output_api)
 
+def _RunHistogramChecks(input_api, output_api, histogram_name):
+  try:
+    # Setup sys.path so that we can call histrogram 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 _CommonChecks(input_api, output_api):
   """Checks common to both upload and commit."""
@@ -75,6 +92,8 @@ def _CommonChecks(input_api, output_api):
         input_api, output_api, file_filter=is_resource).RunChecks())
     results.extend(js_checker.JSChecker(
         input_api, output_api, file_filter=is_resource).RunChecks())
+    results.extend(_RunHistogramChecks(input_api, output_api,
+      "BadMessageReasonChrome"))
   finally:
     sys.path = old_path