android: Histogram for the GSA account change broacast mechanism.

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 f6abeebaf3dcc0f20c42add42959b0044caf334e..83289e610afe08317d73108f6dbb42b56b4f8c64 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -56276,6 +56276,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Search.GsaBroadcastsAccountChanges"
+    enum="BooleanAccountChange">
+  <owner>lizeb@chromium.org</owner>
+  <summary>
+    On Android, whether GSA tells Chrome about account changes through the
+    service or through a broadcast. This is reported at most once per Chrome
+    startup.
+  </summary>
+</histogram>
+
 <histogram name="Search.MigratedPrefToDictionaryValue" enum="BooleanHit">
   <owner>caitkp@chromium.org</owner>
   <summary>
@@ -74720,6 +74730,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1" label="Accepted"/>
 </enum>
 
+<enum name="BooleanAccountChange" type="int">
+  <int value="0" label="Service"/>
+  <int value="1" label="Broadcast"/>
+</enum>
+
 <enum name="BooleanActivation" type="int">
   <int value="0" label="Deactivated"/>
   <int value="1" label="Activated"/>