Record how often we end up in Chrome from external navigations.

tools/metrics/actions/actions.xml

Index: tools/metrics/actions/actions.xml
diff --git a/tools/metrics/actions/actions.xml b/tools/metrics/actions/actions.xml
index 776098b45e4214d264e6a58501a017632edcbae6..1b207a62309ec58af3c895ba15483667df3074c4 100644
--- a/tools/metrics/actions/actions.xml
+++ b/tools/metrics/actions/actions.xml
@@ -8724,6 +8724,14 @@ should be able to be added at any place in this file.
   <obsolete>Deprecated as of 8/2015</obsolete>
 </action>
 
+<action name="MobileExternalNavigationReceived">

[Ilya Sherman, 2016/06/28 21:50:55]

You mentioned there was a parallel user action already in place.  What is the
name of that action, and would it make sense to name this action in parallel to
it?

[Maria, 2016/06/28 23:00:26]

It's actually a histogram called Android.TabNavigationInterceptResult.

[Ilya Sherman, 2016/06/29 20:21:15]

Ah.  It's a bit hard to compare user actions and histograms, as they're not
recorded in exactly the same way.  For example, there are differences in terms
of which metrics are recorded in Incognito mode.  I'd recommend recording any
metrics that you wish to compare using the same underlying mechanism. 
Otherwise, you'll need to make various affordances to be able to actually
compare the data.

+  <owner>mariakhomenko@chromium.org</owner>
+  <description>
+    Records  when a user was given a choice between using Chrome and a system
+    app and chose Chrome.
+  </description>
+</action>
+
 <action name="MobileFirstEditInOmnibox">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>