Switch WebVR to handle GvrApi management through VrShellDelegate

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellInterface.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.widget.FrameLayout;
 
 import org.chromium.chrome.browser.tab.Tab;
 
 /**
  * Abstracts away the VrShell class, which may or may not be present at runtime depending on
  * compile flags.
  */
 public interface VrShellInterface {
     /**
      * Performs native VrShell initialization.
      */
-    void onNativeLibraryReady(Tab currentTab);
+    void initializeNative(Tab currentTab, VrShellDelegate delegate);
 
     /**
      * Pauses VrShell.
      */
     void pause();
 
     /**
      * Resumes VrShell.
      */
     void resume();
 
     /**
      * Destroys VrShell.
      */
     void teardown();
 
     /**
      * Sets Android VR Mode to |enabled|.
      */
     void setVrModeEnabled(boolean enabled);
 
     /**
+     * Sets whether we're presenting WebVR content or not.
+     */
+    void setWebVrModeEnabled(boolean enabled);
+
+    /**
      * Returns the GVRLayout as a FrameLayout.
      */
     FrameLayout getContainer();
 }