[Password Manager] Add UMA signals to understand how often the password form submit navigate…

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index d130d21c84a688be7cf67d56babefed1cace298f..0a7eb4501a7d1a03ef01f33d46fc34fb92abe503 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -22996,6 +22996,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="PasswordManager.SubmitNavigatesToDifferentDomain"

[Ilya Sherman, 2014/12/15 19:31:14]

I think "origin" is a better term than "domain", unless you are measuring
something different from the origin.

[Pritam Nikam, 2014/12/16 07:16:52]

Done.

[vabr (Chromium), 2014/12/16 10:53:37]

Actually, this signal does measure something different than an origin: it checks
if the registry controlled domains are the same or not. This is as in fuzzy
password matching -- m.facebook.com and www.facebook.com would be reported as
the same "domain", but they are not the same origin.

[Ilya Sherman, 2014/12/16 19:56:26]

Ah, thanks for correcting me.  In that case, "domain" is the more correct term. 
Apologies, Pritam, for the bad advice.

+    enum="Boolean">

[Ilya Sherman, 2014/12/15 19:31:14]

Please define and use a custom enumeration, with the labels "Same origin" and
"Different origin".

[Pritam Nikam, 2014/12/16 07:16:52]

Done.

+  <owner>vabr@chromium.org</owner>
+  <summary>
+    Indicates whether submitting a password login form changes the registry
+    controlled domain of the main frame.
+  </summary>
+</histogram>
+
 <histogram name="PasswordManager.SyncCredentialFiltered" enum="Boolean">
   <owner>gcasto@chromium.org</owner>
   <owner>vabr@chromium.org</owner>