Enable magic window mode with new Gvr

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.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;
 
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.content.Context;
@@ skipping 398 matching lines @@
 
         if (FeatureUtilities.isTabModelMergingEnabled()) {
             boolean inMultiWindowMode = MultiWindowUtils.getInstance().isInMultiWindowMode(this);
             // Merge tabs if the activity is not in multi-window mode and mMergeTabsOnResume is true
             // or unset because the activity is just starting or was destroyed.
             if (!inMultiWindowMode && (mMergeTabsOnResume == null || mMergeTabsOnResume)) {
                 maybeMergeTabs();
             }
             mMergeTabsOnResume = false;
         }
-        if (mVrShellDelegate.isInVR()) mVrShellDelegate.resumeVR();
+        mVrShellDelegate.maybeResumeVR();
 
         mLocaleManager.setSnackbarManager(getSnackbarManager());
         mLocaleManager.startObservingPhoneChanges();
     }
 
     @Override
     public void onPauseWithNative() {
         mTabModelSelectorImpl.commitAllTabClosures();
         CookiesFetcher.persistCookies(this);
-        if (mVrShellDelegate.isInVR()) mVrShellDelegate.pauseVR();
+        mVrShellDelegate.maybePauseVR();
 
         mLocaleManager.setSnackbarManager(null);
         mLocaleManager.stopObservingPhoneChanges();
 
         super.onPauseWithNative();
     }
 
     @Override
     public void onStopWithNative() {
         super.onStopWithNative();
@@ skipping 1189 matching lines @@
                     isIncognito ? "new-incognito-tab-shortcut" : "new-tab-shortcut");
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
 
     public VrShellDelegate getVrShellDelegate() {
         return mVrShellDelegate;
     }
 }