[Smart Lock, Settings Reconciliation] Histograms for tracking initial pref values.

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 49b59a31024ffe7d749bbb3955d0ad121d526a79..370c13e7e03f979a9f1b3ac7c2740f810df436f3 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -30244,6 +30244,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="PasswordManager.SettingsReconciliation.InitialValues"
+    enum="PasswordManagerPreferencesInitialValues">
+  <owner>engedy@chromium.org</owner>
+  <owner>melandory@chromium.org</owner>
+  <summary>
+    Tracks the initial values for both password manager settings.

[engedy, 2015/09/24 14:26:18]

Also explain when / how many samples are recorded.

nit: I'd move the summary from the enum to here. I'm not really sure where the
summary for the enum is displayed on the histograms dashboard, if at all.

[melandory, 2015/09/28 07:10:12]

Done.

+  </summary>
+</histogram>
+
 <histogram name="PasswordManager.StoreReadyWhenWiping" enum="Boolean">
   <owner>vabr@chromium.org</owner>
   <summary>
@@ -66875,6 +66884,18 @@ To add a new entry, add it with any value and run test to compute valid value.
       label="Password status not checked as user is on a Windows Domain"/>
 </enum>
 
+<enum name="PasswordManagerPreferencesInitialValues" type="int">
+  <summary>
+    The pair of initial values for the legacy preference for controlling the
+    Chrome Password Manager and new preference for controlling Smart Lock on
+    Android.
+  </summary>
+  <int value="0" label="N0L0"/>

[engedy, 2015/09/24 14:26:18]

nit: I'd suggest to be a bit more verbose here with the labels, so it will be
obvious even to non-technical people what each value means on the dashboard.

[melandory, 2015/09/28 07:10:12]

Done.

+  <int value="1" label="N0L1"/>
+  <int value="2" label="N1L0"/>
+  <int value="3" label="N1L1"/>
+</enum>
+
 <enum name="PasswordManagerPslDomainMatchTriggering" type="int">
   <summary>
     The value indicates whether an entry returned by password autofill contains