[Android] Histogram for Android restore

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 35bf3ee00b5c96f35104ccaf8a92476c6e6b2fea..a4c9707e06a709b2deeed5133163066d8611dccb 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -788,6 +788,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Android.RestoreResult" enum="AndroidRestoreResult">
+  <owner>aberent@chromium.org</owner>
+  <summary>
+    Whether Chrome tried to restore its settings from a previous device or
+    installation, and what happened when it did. Only recorded on first run.
+  </summary>
+</histogram>
+
 <histogram name="Android.SeccompStatus.Prctl" enum="AndroidSeccompStatus">
   <owner>rsesek@chromium.org</owner>
   <summary>
@@ -80744,6 +80752,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="3" label="LowMemory"/>
 </enum>
 
+<enum name="AndroidRestoreResult" type="int">
+  <int value="0" label="No restore attempted"/>
+  <int value="1" label="Restore successful"/>
+  <int value="2" label="Failed: Chrome already run locally"/>
+  <int value="3" label="Failed: Chrome startup failed"/>
+  <int value="4" label="Failed: Cannot sign in as former user"/>

[Bernhard Bauer, 2017/03/16 11:36:36]

Nit: "previous user" maybe? "Former user" sounds a bit like the ex-parrot ;-)

[aberent, 2017/03/16 12:16:50]

Done.

+</enum>
+
 <enum name="AndroidSeccompSandboxStatus" type="int">
   <int value="0" label="Not Supported"/>
   <int value="1" label="Detection Failed"/>