✈ Remove unnecessary flag and DocumentModeManager.

chrome/android/javatests/src/org/chromium/chrome/browser/tab/TabUmaTest.java

 // Copyright 2015 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.tab;
 
 import android.os.Environment;
 import android.test.suitebuilder.annotation.MediumTest;
 
 import org.chromium.base.ThreadUtils;
-import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.MetricsUtils.HistogramDelta;
 import org.chromium.chrome.browser.ChromeActivity;
-import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabSelectionType;
 import org.chromium.chrome.test.ChromeActivityTestCaseBase;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.net.test.EmbeddedTestServer;
 
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 
 /**
@@ skipping 26 matching lines @@
     @Override
     protected void tearDown() throws Exception {
         mTestServer.stopAndDestroyServer();
         super.tearDown();
     }
 
     /**
      * Verify that Tab.StatusWhenSwitchedBackToForeground is correctly recording lazy loads.
      */
     @MediumTest
-    @CommandLineFlags.Add(ChromeSwitches.DISABLE_DOCUMENT_MODE)
     @Feature({"Uma"})
     public void testTabStatusWhenSwitchedToLazyLoads() throws ExecutionException {
         final Tab tab = ThreadUtils.runOnUiThreadBlocking(new Callable<Tab>() {
             @Override
             public Tab call() {
                 Tab bgTab = Tab.createTabForLazyLoad(getActivity(), false,
                         getActivity().getWindowAndroid(), TabLaunchType.FROM_LONGPRESS_BACKGROUND,
                         Tab.INVALID_TAB_ID, new LoadUrlParams(mTestUrl));
                 bgTab.initialize(null, null, new TabDelegateFactory(), true, false);
                 return bgTab;
@@ skipping 101 matching lines @@
                 liveBgTab.show(TabSelectionType.FROM_USER);
                 killedBgTab.show(TabSelectionType.FROM_USER);
                 frozenBgTab.show(TabSelectionType.FROM_USER);
             }
         });
         assertEquals(1, shownLoadCount.getDelta());
         assertEquals(1, lostLoadCount.getDelta());
         assertEquals(1, skippedLoadCount.getDelta());
     }
 }