Implement lazy initialization for VrShellDelegate

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrDaydreamApiImpl.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.vr_shell;
 
 import android.app.Activity;
 import android.app.PendingIntent;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.os.StrictMode;
 
 import com.google.vr.ndk.base.DaydreamApi;
 import com.google.vr.ndk.base.GvrApi;
 
 import junit.framework.Assert;
 
 import org.chromium.ui.base.WindowAndroid;
 
 
 /**
  * A wrapper for DaydreamApi. Note that we have to recreate the DaydreamApi instance each time we
  * use it, or API calls begin to silently fail.
  */
 public class VrDaydreamApiImpl implements VrDaydreamApi {
-    private static final String TAG = "VrDaydreamApiImpl";
     private final Context mContext;
 
     public VrDaydreamApiImpl(Context context) {
         mContext = context;
     }
 
     @Override
     public boolean isDaydreamReadyDevice() {
         return DaydreamApi.isDaydreamReadyPlatform(mContext);
     }
@@ skipping 25 matching lines @@
     public boolean launchInVr(final PendingIntent pendingIntent) {
         DaydreamApi daydreamApi = DaydreamApi.create(mContext);
         if (daydreamApi == null) return false;
         daydreamApi.launchInVr(pendingIntent);
         daydreamApi.close();
         return true;
     }
 
     @Override
     public boolean exitFromVr(int requestCode, final Intent intent) {
-        DaydreamApi daydreamApi = DaydreamApi.create(mContext);
-        if (daydreamApi == null) return false;
         Activity activity = WindowAndroid.activityFromContext(mContext);
         Assert.assertNotNull(activity);
+        DaydreamApi daydreamApi = DaydreamApi.create(activity);
+        if (daydreamApi == null) return false;
         daydreamApi.exitFromVr(activity, requestCode, intent);
         daydreamApi.close();
         return true;
     }
 
     @Override
     public Boolean isDaydreamCurrentViewer() {
         DaydreamApi daydreamApi = DaydreamApi.create(mContext);
         if (daydreamApi == null) return false;
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
@@ skipping 11 matching lines @@
     }
 
     @Override
     public void launchVrHomescreen() {
         DaydreamApi daydreamApi = DaydreamApi.create(mContext);
         if (daydreamApi == null) return;
         daydreamApi.launchVrHomescreen();
         daydreamApi.close();
     }
 }