Fix crash when set VR mode to false after VrShell is destroyed

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilder.java

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilder.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilder.java
deleted file mode 100644
index a2c4de721f9c9578fd99c4c1a5fa73448ecdd9eb..0000000000000000000000000000000000000000
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilder.java
+++ /dev/null
@@ -1,31 +0,0 @@
-// 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;
-
-/**
- * Abstracts away the VrClassesBuilderImpl class, which may or may not be present at runtime
- * depending on compile flags.
- */
-public interface VrClassesBuilder {
-    /**
-     * Creates a NonPresentingGvrContextImpl instance.
-     */
-    public NonPresentingGvrContext createNonPresentingGvrContext();
-
-    /**
-     * Creates a VrShellImpl instance.
-     */
-    public VrShell createVrShell();
-
-    /**
-     * Creates a VrDaydreamApImpl instance.
-     */
-    public VrDaydreamApi createVrDaydreamApi();
-
-    /**
-    * Creates a VrCoreVersionCheckerImpl instance.
-    */
-    public VrCoreVersionChecker createVrCoreVersionChecker();
-}