Swap to foreground tab when following links that open in a new tab/window in VR Shell.

chrome/browser/android/vr_shell/vr_compositor.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_
 
 #include <memory>
 
 #include "base/android/scoped_java_ref.h"
@@ skipping 27 matching lines @@
   void SetWindowBounds(gfx::Size size);
   gfx::Size GetWindowBounds() { return bounds_; }
   void SurfaceChanged(jobject surface);
   void SetLayer(content::WebContents* web_contents);
 
   // CompositorClient implementation:
   void UpdateLayerTreeHost() override;
   void OnSwapBuffersCompleted(int pending_swap_buffers) override;
 
  private:
+  void RestoreLayer();
+
   std::unique_ptr<content::Compositor> compositor_;
   gfx::Size bounds_;
 
   cc::Layer* layer_ = nullptr;
   cc::Layer* layer_parent_ = nullptr;
   SkColor background_color_;
   bool transparent_;
 
   DISALLOW_COPY_AND_ASSIGN(VrCompositor);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_COMPOSITOR_H_