[Sync] Removing complexity around PROXY_TABS now that empty sessions are provided when disabled.

chrome/test/data/webui/md_history/history_metrics_test.js

 // 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.
 
 /**
  * @constructor
  * @extends {md_history.BrowserService}
  */
 var TestMetricsBrowserService = function() {
   this.histogramMap = {};
@@ skipping 150 matching lines @@
             [createWindow(['http://www.google.com', 'http://example.com'])]
         ),
         createSession(
             'Nexus 6',
             [
               createWindow(['http://test.com']),
               createWindow(['http://www.gmail.com', 'http://badssl.com'])
             ]
         ),
       ];
-      setForeignSessions(sessionList, true);
+      setForeignSessions(sessionList);
       return PolymerTest.flushTasks();
     }).then(() => {
       assertEquals(1, histogram[SyncedTabsHistogram.HAS_FOREIGN_DATA]);
       return PolymerTest.flushTasks();
     }).then(() => {
       cards = polymerSelectAll(
           app.$$('#synced-devices'), 'history-synced-device-card');
       MockInteractions.tap(cards[0].$['card-heading']);
       assertEquals(1, histogram[SyncedTabsHistogram.COLLAPSE_SESSION]);
       MockInteractions.tap(cards[0].$['card-heading']);
       assertEquals(1, histogram[SyncedTabsHistogram.EXPAND_SESSION]);
       MockInteractions.tap(polymerSelectAll(cards[0], '.website-title')[0]);
       assertEquals(1, histogram[SyncedTabsHistogram.LINK_CLICKED]);
 
       MockInteractions.tap(cards[0].$['menu-button']);
       return PolymerTest.flushTasks();
     }).then(() => {
       MockInteractions.tap(app.$$('#synced-devices').$$('#menuOpenButton'));
       assertEquals(1, histogram[SyncedTabsHistogram.OPEN_ALL]);
 
       MockInteractions.tap(app.$$('#synced-devices').$$('#menuDeleteButton'));
       assertEquals(1, histogram[SyncedTabsHistogram.HIDE_FOR_NOW]);
     });
   });
 });