[Autofill] Log count histogram for the number of server cards

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 dbf554246285e39c0fa2b17c7777b698507c2ce5..aa438a7f26aca0436ea4fbbcc432f88eb020d677 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -3470,7 +3470,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="Autofill.StoredLocalCreditCardCount">
+<histogram name="Autofill.StoredLocalCreditCardCount" units="cards">
   <owner>mathp@chromium.org</owner>
   <summary>
     The number of local credit cards a user has stored, measured at Chrome
@@ -3493,6 +3493,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Autofill.StoredServerCreditCardCount" units="cards">
+  <owner>mathp@chromium.org</owner>
+  <summary>
+    The number of server credit cards a user has stored, measured at Chrome
+    profile launch time.
+  </summary>
+</histogram>
+
 <histogram name="Autofill.SuggestionAcceptedIndex" units="position">
   <owner>mathp@chromium.org</owner>
   <summary>The index of the accepted Autofill suggestion in the popup.</summary>
@@ -102465,6 +102473,12 @@ value.
   <affected-histogram name="Autofill.Quality.ServerType.ByFieldType"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="AutofillStoredServerCardType" separator=".">
+  <suffix name="Masked" label="Masked cards"/>
+  <suffix name="Unmasked" label="Unmasked cards (locally cached)"/>
+  <affected-histogram name="Autofill.StoredServerCreditCardCount"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="AutofillUnmaskPromptCloseReasonEvents" separator=".">
   <suffix name="Failure" label="Failure"/>
   <suffix name="NoAttempts" label="No attempts"/>