Add VrShell feature flag and wire it up to VrShell delegate.

content/public/common/content_features.h

 // Copyright 2015 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.
 
 // This file defines all the public base::FeatureList features for the content
 // module.
 
 #ifndef CONTENT_PUBLIC_COMMON_CONTENT_FEATURES_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_FEATURES_H_
 
@@ skipping 34 matching lines @@
 CONTENT_EXPORT extern const base::Feature kRafAlignedTouchInputEvents;
 CONTENT_EXPORT extern const base::Feature kRenderingPipelineThrottling;
 CONTENT_EXPORT extern const base::Feature kScrollAnchoring;
 CONTENT_EXPORT extern const base::Feature kServiceWorkerNavigationPreload;
 CONTENT_EXPORT extern const base::Feature kSharedArrayBuffer;
 CONTENT_EXPORT extern const base::Feature kSpeculativeLaunchServiceWorker;
 CONTENT_EXPORT extern const base::Feature kStaleWhileRevalidate;
 CONTENT_EXPORT extern const base::Feature kTimerThrottlingForHiddenFrames;
 CONTENT_EXPORT extern const base::Feature kTokenBinding;
 CONTENT_EXPORT extern const base::Feature kTouchpadAndWheelScrollLatching;
+CONTENT_EXPORT extern const base::Feature kVrShell;
 CONTENT_EXPORT extern const base::Feature kWebAssembly;
 CONTENT_EXPORT extern const base::Feature kWebGLImageChromium;
 CONTENT_EXPORT extern const base::Feature kWebRtcEcdsaDefault;
 CONTENT_EXPORT extern const base::Feature kWebRtcUseGpuMemoryBufferVideoFrames;
 CONTENT_EXPORT extern const base::Feature kWebUsb;
 CONTENT_EXPORT
 extern const base::Feature kSendBeaconThrowForBlobWithNonSimpleType;
 
 #if defined(OS_ANDROID)
 CONTENT_EXPORT extern const base::Feature kAutoplayMutedVideos;
 CONTENT_EXPORT extern const base::Feature kImeThread;
 CONTENT_EXPORT extern const base::Feature kSeccompSandboxAndroid;
 CONTENT_EXPORT extern const base::Feature kWebPayments;
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_WIN)
 CONTENT_EXPORT extern const base::Feature kWinSboxDisableExtensionPoints;
 #endif  // defined(OS_WIN)
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace features
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_FEATURES_H_