Added uma for pin unlock set up.

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 b1e5861e2ac2b8174eed1c156b6bd14f0455c489..da7252e7c55ccb8ad8860b730882197e87dcb243 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -55342,6 +55342,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>The number of pinned tabs opened when a profile is loaded.</summary>
 </histogram>
 
+<histogram name="Settings.PinUnlockSetup" enum="LockScreenProgress">
+  <owner>sammiequon@chromium.org</owner>
+  <summary>
+    The users progress through the pin unlock setup wizard. Each type
+    corresponds to the user completeing a different stage of the setup wizard.
+  </summary>
+</histogram>
+
 <histogram name="Settings.RegisterProfilePrefsTime" units="ms">
   <owner>rkaplow@chromium.org</owner>
   <summary>
@@ -85894,6 +85902,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1" label="SinkNeverStarted"/>
 </enum>
 
+<enum name="LockScreenProgress" type="int">
+  <int value="0" label="Start screen lock"/>
+  <int value="1" label="Enter password correctly"/>
+  <int value="2" label="Choose pin or password"/>
+  <int value="3" label="Enter pin"/>
+  <int value="4" label="Confirm pin"/>
+</enum>
+
 <enum name="LoginConsumerWhitelist" type="int">
   <int value="0" label="ANY_USER_ALLOWED">Any user can sign in</int>
   <int value="1" label="ONLY_WHITELISTED_ALLOWED">Whitelisted users only</int>