VR: Split off UI code into a library to ease future unit testing.

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 91 matching lines @@
                                     const gfx::Vector3dF& ray_vector,
                                     float* distance) const {
   return GetRayPlaneDistance(ray_origin, ray_vector, GetCenter(), GetNormal(),
                              distance);
 }
 
 UiElement::UiElement() = default;
 
 UiElement::~UiElement() = default;
 
-void UiElement::Render(VrShellRenderer* renderer,
+void UiElement::Render(UiElementRenderer* renderer,
                        vr::Mat4f view_proj_matrix) const {
   NOTREACHED();
 }
 
 void UiElement::Initialize() {}
 
 void UiElement::OnHoverEnter(const gfx::PointF& position) {}
 
 void UiElement::OnHoverLeave() {}
 
@@ skipping 111 matching lines @@
 void UiElement::SetMode(ColorScheme::Mode mode) {
   if (mode_ == mode)
     return;
   mode_ = mode;
   OnSetMode();
 }
 
 void UiElement::OnSetMode() {}
 
 }  // namespace vr_shell