Remove Sync GetPose VRService call, implement VRVSyncProvider

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/NonPresentingGvrContextImpl.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 com.google.vr.ndk.base.GvrLayout;
 
 /**
  * Creates an active GvrContext from a detached GvrLayout. This is used by magic window mode.
  */
 public class NonPresentingGvrContextImpl implements NonPresentingGvrContext {
     private GvrLayout mGvrLayout;
 
     public NonPresentingGvrContextImpl(Activity activity) {
         mGvrLayout = new GvrLayout(activity);
     }
 
     @Override
     public long getNativeGvrContext() {
         return mGvrLayout.getGvrApi().getNativeGvrContext();
     }
 
     @Override
-    public void resume() {
-        mGvrLayout.getGvrApi().resumeTracking();
-    }
-
-    @Override
-    public void pause() {
-        // We can't pause/resume the GvrLayout, because doing so will force us to enter VR. However,
-        // we should be safe not pausing it as we never add it to the view hierarchy, or give it a
-        // presentation view, so there's nothing to pause but the tracking.
-        mGvrLayout.getGvrApi().pauseTracking();
-    }
-
-    @Override
     public void shutdown() {
         mGvrLayout.shutdown();
     }
 }