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

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.gsa;
 
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
@@ skipping 43 matching lines @@
         return sInstance;
     }
 
     private GSAAccountChangeListener(Context context) {
         Context applicationContext = context.getApplicationContext();
         BroadcastReceiver accountChangeReceiver = new BroadcastReceiver() {
             @Override
             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);
             }
         };
         applicationContext.registerReceiver(accountChangeReceiver,
                 new IntentFilter(ACCOUNT_UPDATE_BROADCAST_INTENT),
                 ACCOUNT_UPDATE_BROADCAST_PERMISSION, null);
 
         createGsaClientAndConnect(applicationContext);
 
         // If some future version of GSA no longer broadcasts the account change
@@ skipping 65 matching lines @@
     public void disconnect() {
         mUsersCount--;
         if (mClient != null && mUsersCount == 0) mClient.disconnect();
     }
 
     private void notifyGsaBroadcastsAccountChanges() {
         mClient.disconnect();
         mClient = null;
     }
 }