Record UMA in ArcNavigationThrottle::OnDisambigDialogClosed

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 4efad5d71eff4c442afd7346449956087716a504..ed68c1c1f85942273c6176a58bd9306d8ca6e9f3 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -970,6 +970,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Arc.IntentHandlerAction" enum="ArcIntentHandlerAction">
+  <owner>elijahtaylor@google.com</owner>
+  <owner>mitsuji@google.com</owner>
+  <summary>Arc intent handler action taken by user.</summary>
+</histogram>
+
 <histogram name="Arc.LowMemoryKiller.Count">
   <owner>elijahtaylor@google.com</owner>
   <owner>mitsuji@google.com</owner>
@@ -65206,6 +65212,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="4" label="Outside of NTP (e.g. bookmarks bar)"/>
 </enum>
 
+<enum name="ArcIntentHandlerAction" type="int">
+  <summary>Defines Arc intent handler actions</summary>
+  <int value="0" label="Always"/>
+  <int value="1" label="Just once"/>
+  <int value="2" label="Preferred activity found"/>
+  <int value="3" label="Dialog deactivated"/>
+  <int value="4" label="Error"/>

[Ilya Sherman, 2016/06/28 03:17:16]

nit: I'd recommend sorting "Error" to be the first item in the enum.  That way,
if you ever add items, it won't end up somewhere oddly in the middle.

[Yusuke Sato, 2016/06/28 05:04:23]

Good idea. Done.

+</enum>
+
 <enum name="ArcOptInAction" type="int">
   <summary>Defines Arc OptIn actions</summary>
   <int value="0" label="Opted In"/>