android: Record the source of account change notifications from GSA.

chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java

Index: chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java b/chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java
index 5cc600f35125f0a51609811e6c9b7bb8a1e26b9d..9824a1fe340b13dc71f1bdb6afc86e8e997dde93 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/gsa/GSAAccountChangeListener.java
@@ -61,6 +61,9 @@ public class GSAAccountChangeListener {
             public void onReceive(Context context, Intent intent) {
                 if (!ACCOUNT_UPDATE_BROADCAST_INTENT.equals(intent.getAction())) return;
                 String accountName = intent.getStringExtra(BROADCAST_INTENT_ACCOUNT_NAME_EXTRA);
+                RecordHistogram.recordEnumeratedHistogram(GSAServiceClient.ACCOUNT_CHANGE_HISTOGRAM,
+                        GSAServiceClient.ACCOUNT_CHANGE_SOURCE_BROADCAST,
+                        GSAServiceClient.ACCOUNT_CHANGE_SOURCE_COUNT);
                 GSAState.getInstance(context.getApplicationContext()).setGsaAccount(accountName);
             }
         };