Update histograms.xml for recent BadMessage values.

content/browser/bad_message.h

Index: content/browser/bad_message.h
diff --git a/content/browser/bad_message.h b/content/browser/bad_message.h
index 8084d8b3d8d1af247447626616fda1f5f195d7ab..6af964585f0af1ba0e9470e7bf50caa2e7c15472 100644
--- a/content/browser/bad_message.h
+++ b/content/browser/bad_message.h
@@ -18,7 +18,7 @@ namespace bad_message {
 //
 // NOTE: Do not remove or reorder elements in this list. Add new entries at the
 // end. Items may be renamed but do not change the values. We rely on the enum
-// values in histograms.
+// values in histograms. Also update histograms.xml with any new values.
 enum BadMessageReason {
   NC_IN_PAGE_NAVIGATION = 0,

[Mark P, 2015/05/11 22:19:01]

It's good practice to explicitly do = 0, = 1, etc. all the way down.  This way
if someone inadvertently removes an item from the enum, it doesn't screw
everything up.  (That said, you still shouldn't remove items.)

ditto on other file

[Charlie Reis, 2015/05/11 22:37:57]

Done.

   RFH_CAN_COMMIT_URL_BLOCKED,