Make VR screen tap tests more stable

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.Context;
@@ skipping 773 matching lines @@
 
     /**
      * @param api The VrDaydreamApi object this delegate will use instead of the default one
      */
     @VisibleForTesting
     public void overrideDaydreamApiForTesting(VrDaydreamApi api) {
         mVrDaydreamApi = api;
     }
 
     /**
+     * @return The VrShell for the VrShellDelegate instance
+     */
+    @VisibleForTesting
+    public static VrShell getVrShellForTesting() {
+        return sInstance == null ? null : sInstance.mVrShell;
+    }
+
+    /**
      * @return Pointer to the native VrShellDelegate object.
      */
     @CalledByNative
     private long getNativePointer() {
         return mNativeVrShellDelegate;
     }
 
     private void destroy() {
         if (sInstance == null) return;
         if (mNativeVrShellDelegate != 0) nativeDestroy(mNativeVrShellDelegate);
         ApplicationStatus.unregisterActivityStateListener(this);
         sInstance = null;
     }
 
     private native long nativeInit();
     private static native void nativeOnLibraryAvailable();
     private native void nativeSetPresentResult(long nativeVrShellDelegate, boolean result);
     private native void nativeDisplayActivate(long nativeVrShellDelegate);
     private native void nativeUpdateVSyncInterval(long nativeVrShellDelegate, long timebaseNanos,
             double intervalSeconds);
     private native void nativeOnPause(long nativeVrShellDelegate);
     private native void nativeOnResume(long nativeVrShellDelegate);
     private native void nativeDestroy(long nativeVrShellDelegate);
 }