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

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilderImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilderImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilderImpl.java
deleted file mode 100644
index 067749b5ba56c11a87ff12b8b1a22f3270a552b9..0000000000000000000000000000000000000000
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrClassesBuilderImpl.java
+++ /dev/null
@@ -1,62 +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;
-
-import android.app.Activity;
-import android.os.StrictMode;
-
-import org.chromium.base.Log;
-import org.chromium.base.annotations.UsedByReflection;
-
-/**
- * Builder class to create all VR related classes. These VR classes are behind the same build time
- * flag as this class. So no reflection is necessary when create them.
- */
-@UsedByReflection("VrShellDelegate.java")
-public class VrClassesBuilderImpl implements VrClassesBuilder {
-    private static final String TAG = "VrClassesBuilderImpl";
-    private final Activity mActivity;
-
-    @UsedByReflection("VrShellDelegate.java")
-    public VrClassesBuilderImpl(Activity activity) {
-        mActivity = activity;
-    }
-
-    @Override
-    public NonPresentingGvrContext createNonPresentingGvrContext() {
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        try {
-            return new NonPresentingGvrContextImpl(mActivity);
-        } catch (Exception ex) {
-            Log.e(TAG, "Unable to instantiate NonPresentingGvrContextImpl", ex);
-            return null;
-        } finally {
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
-    }
-
-    @Override
-    public VrShell createVrShell() {
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        try {
-            return new VrShellImpl(mActivity);
-        } catch (Exception ex) {
-            Log.e(TAG, "Unable to instantiate VrShellImpl", ex);
-            return null;
-        } finally {
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
-    }
-
-    @Override
-    public VrDaydreamApi createVrDaydreamApi() {
-        return new VrDaydreamApiImpl(mActivity);
-    }
-
-    @Override
-    public VrCoreVersionChecker createVrCoreVersionChecker() {
-        return new VrCoreVersionCheckerImpl();
-    }
-}