Notify VRDeviceProviders when there are pages listening for vrdisplayactivate

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.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.Intent;
@@ skipping 59 matching lines @@
     private NonPresentingGvrContext mNonPresentingGvrContext;
     private VrDaydreamApi mVrDaydreamApi;
     private VrCoreVersionChecker mVrCoreVersionChecker;
     private boolean mInVr;
     private int mRestoreSystemUiVisibilityFlag = -1;
     private int mRestoreOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
     private long mNativeVrShellDelegate;
     private Tab mTab;
     private boolean mRequestedWebVR;
     private long mLastVRExit;
+    private boolean mListeningForWebVrActivate;
 
     public VrShellDelegate(ChromeTabbedActivity activity) {
         mActivity = activity;
         mVrAvailable = maybeFindVrClasses() && isVrCoreCompatible();
         createVrDaydreamApi();
         mTabObserver = new EmptyTabObserver() {
             @Override
             public void onContentChanged(Tab tab) {
                 if (tab.getNativePage() != null || tab.isShowingSadTab()) {
                     // For now we don't handle native pages. crbug.com/661609
@@ skipping 269 matching lines @@
         }
         return mNonPresentingGvrContext.getNativeGvrContext();
     }
 
     @CalledByNative
     private void shutdownNonPresentingNativeContext() {
         mNonPresentingGvrContext.shutdown();
         mNonPresentingGvrContext = null;
     }
 
+    @CalledByNative
+    private void setListeningForWebVrActivate(boolean listening) {
+        mListeningForWebVrActivate = listening;

[dcheng, 2016/11/17 19:08:04]

is this write-only? Will it be used in a followup?

[bajones, 2016/11/17 19:23:28]

Yes, the intent is to use it in a followup. (Needs
https://codereview.chromium.org/2510873003 to land before it can be used, IIRC)

+    }
+
     /**
      * Exits VR Shell, performing all necessary cleanup.
      */
     private void shutdownVR(boolean returnTo2D) {
         if (!mInVr) return;
         if (returnTo2D) {
             mVrDaydreamApi.exitFromVr(EXIT_VR_RESULT, new Intent());
         } else {
             mVrDaydreamApi.setVrModeEnabled(false);
             mLastVRExit = SystemClock.uptimeMillis();
@@ skipping 151 matching lines @@
     /**
      * @return Pointer to the native VrShellDelegate object.
      */
     @CalledByNative
     private long getNativePointer() {
         return mNativeVrShellDelegate;
     }
 
     private native long nativeInit();
 }