arc: Skip GMS Sign-In in case Android is already signed-in.

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 878604d99644e15ecdff50b057639a60701dcc83..6a20447fb319c5d4a75111b2481996bb17b8fea3 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -1639,6 +1639,19 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="ArcAuth.AccountCheckStatus" enum="ArcAuthAccountCheckStatus">
+  <owner>elijahtaylor@google.com</owner>
+  <summary>The status of account check before GMS Sign-in.</summary>
+</histogram>
+
+<histogram name="ArcAuth.AccountCheckTime" units="ms">
+  <owner>elijahtaylor@chromium.org</owner>
+  <summary>
+    Elapsed time waiting for the account status check to be completed. This is
+    not recorded in case of account status check failure.
+  </summary>
+</histogram>
+
 <histogram name="ArcAuth.CheckinAttempts" units="attempts">
   <owner>elijahtaylor@chromium.org</owner>
   <summary>
@@ -81513,6 +81526,15 @@ 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="ArcAuthAccountCheckStatus" type="int">
+  <summary>Defines ARC account check statuses</summary>

[Ilya Sherman, 2017/03/24 23:22:09]

nit: I don't think this <summary> text is used anywhere, so it's fine to omit. 
(It's also fine to keep, if you prefer it for whatever reason.)

[khmel, 2017/03/24 23:51:53]

Good point!

+  <int value="0" label="Account is up to date"/>
+  <int value="1" label="New account"/>
+  <int value="2" label="Account needs reauth"/>
+  <int value="3" label="Account has unknown state"/>
+  <int value="4" label="Account check failed"/>
+</enum>
+
 <enum name="ArcIntentHandlerAction" type="int">
   <summary>Defines Arc intent handler actions</summary>
   <int value="0" label="Error"/>