Add Chrome OS enrollment status UMA stat

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 477ad058849b3f1a0caa0bdd1ed7a5a9ddbe5bb0..59db2d9eaa6225cd16d6880ce7c7580ca9c5a4da 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -40340,6 +40340,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="UMA.EnrollmentStatus" enum="EnrollmentStatus">
+  <owner>asvitkine@chromium.org</owner>
+  <owner>kaznacheev@chromium.org</owner>
+  <summary>
+    Logs the device enrollment status for Chrome OS device. Logged with every
+    UMA upload.
+  </summary>
+</histogram>
+
 <histogram name="UMA.EntropySourceType" enum="UmaEntropySourceType">
   <owner>asvitkine@chromium.org</owner>
   <summary>
@@ -46934,6 +46943,13 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="6" label="SCRIPT_EVALUATED"/>
 </enum>
 
+<enum name="EnrollmentStatus" type="int">
+  <int value="0" label="Non-managed"/>
+  <int value="1" label="Managed EDU"/>
+  <int value="2" label="Managed non-EDU"/>
+  <int value="3" label="Error"/>
+</enum>
+
 <enum name="EnterpriseCheckError" type="int">
   <summary>
     Defined as DomainCheckErrors in