Add a metric for autofilled Android credentials.

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 f956cff2a0b6455d02a7125daacbc0244449c501..e723014d374184b912a345147ebf1148756502bd 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -27422,6 +27422,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="PasswordManager.FillSuggestionsIncludeAndroidAppCredentials"
+    enum="PasswordManagerOfferedAndroidCredentials">
+  <owner>msramek@chromium.org</owner>
+  <owner>engedy@chromium.org</owner>
+  <summary>
+    When offering to fill the username and password, whether at least one of the
+    credentials in the dropdown comes from an Android app.
+  </summary>
+</histogram>
+
 <histogram name="PasswordManager.FormDataDeserializationStatus"
     enum="FormDataDeserializationStatus">
   <owner>gcasto@chromium.org</owner>
@@ -62121,6 +62131,11 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1" label="A password change form"/>
 </enum>
 
+<enum name="PasswordManagerOfferedAndroidCredentials" type="int">
+  <int value="0" label="None from Android"/>
+  <int value="1" label="1+ from Android"/>
+</enum>
+
 <enum name="PasswordManagerOsPasswordStatus" type="int">
   <int value="0" label="Unknown"/>
   <int value="1" label="Unsupported platform"/>