VR: Wire VrShell UI-related state to the scene manager.

chrome/browser/android/vr_shell/vr_shell.h

Index: chrome/browser/android/vr_shell/vr_shell.h
diff --git a/chrome/browser/android/vr_shell/vr_shell.h b/chrome/browser/android/vr_shell/vr_shell.h
index 104f2b95a3867e7363498426793f72effe266bc5..172076415a7fcdb705a578ecff4c9bf0ce214278 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -128,7 +128,6 @@ class VrShell : public device::PresentingGvrDelegate,
 
   void ContentSurfaceChanged(jobject surface);
   void GvrDelegateReady();
-  void AppButtonGesturePerformed(UiInterface::Direction direction);
 
   void ContentPhysicalBoundsChanged(
       JNIEnv* env,
@@ -183,7 +182,6 @@ class VrShell : public device::PresentingGvrDelegate,
 
   bool vr_shell_enabled_;
 
-  std::unique_ptr<UiInterface> ui_;
   bool content_paused_ = false;
   bool webvr_mode_ = false;
 
@@ -203,6 +201,7 @@ class VrShell : public device::PresentingGvrDelegate,
 
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
   std::unique_ptr<VrGLThread> gl_thread_;
+  UiInterface* ui_;
   bool reprojected_rendering_;
 
   jobject content_surface_ = nullptr;