Enable gpu rasterization in the vr shell

chrome/browser/android/vr_shell/ui_elements/ui_element.cc

 // 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.
 
 #include "chrome/browser/android/vr_shell/ui_elements/ui_element.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 96 matching lines @@
 
 UiElement::UiElement() = default;
 
 UiElement::~UiElement() = default;
 
 void UiElement::Render(VrShellRenderer* renderer,
                        vr::Mat4f view_proj_matrix) const {
   NOTREACHED();
 }
 
+void UiElement::Initialize(VrSurfaceProvider* provider) {
+  surface_provider_ = provider;
+  Initialize();
+}
+
 void UiElement::Initialize() {}
 
 void UiElement::OnHoverEnter() {}
 
 void UiElement::OnHoverLeave() {}
 
 void UiElement::OnButtonDown() {}
 
 void UiElement::OnButtonUp() {}
 
@@ skipping 85 matching lines @@
 
 bool UiElement::IsVisible() const {
   return visible_ && computed_opacity_ > 0.0f;
 }
 
 bool UiElement::IsHitTestable() const {
   return IsVisible() && hit_testable_;
 }
 
 }  // namespace vr_shell