Enable gpu rasterization in the vr shell

chrome/browser/android/vr_shell/ui_elements/ui_element.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_UI_ELEMENTS_UI_ELEMENT_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_UI_ELEMENT_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "device/vr/vr_types.h"
 
 namespace base {
 class TimeTicks;
 }
 
 namespace vr_shell {
 
 class Animation;
 class VrShellRenderer;
+class VrSurfaceProvider;
 
 enum XAnchoring {
   XNONE = 0,
   XLEFT,
   XRIGHT,
 };
 
 enum YAnchoring {
   YNONE = 0,
   YTOP,
@@ skipping 64 matching lines @@
 
   // Indicates whether the element should be visually rendered.
   bool IsVisible() const;
 
   // Indicates whether the element should be tested for cursor input.
   bool IsHitTestable() const;
 
   virtual void Render(VrShellRenderer* renderer,
                       vr::Mat4f view_proj_matrix) const;
 
-  virtual void Initialize();
+  void Initialize(VrSurfaceProvider* provider);
 
   // Controller interaction methods.
   virtual void OnHoverEnter();
   virtual void OnHoverLeave();
   virtual void OnButtonDown();
   virtual void OnButtonUp();
 
   int id() const { return id_; }
   void set_id(int id) { id_ = id; }
 
@@ skipping 94 matching lines @@
     return inheritable_transform_;
   }
   void set_inheritable_transform(const Transform& transform) {
     inheritable_transform_ = transform;
   }
 
   // A flag usable during transformation calculates to avoid duplicate work.
   bool dirty() const { return dirty_; }
   void set_dirty(bool dirty) { dirty_ = dirty; }
 
+ protected:
+  virtual void Initialize();
+
+  // This obtains a GPU-backed surface. Only valid after initialized.
+  VrSurfaceProvider* surface_provider() { return surface_provider_; }
+
  private:
   // Valid IDs are non-negative.
   int id_ = -1;
 
   // If a non-negative parent ID is specified, applicable transformations
   // are applied relative to the parent, rather than absolutely.
   int parent_id_ = -1;
 
   // If true, this object will be visible.
   bool visible_ = true;
@@ skipping 46 matching lines @@
   int draw_phase_ = 1;
 
   // This transform can be used by children to derive position of its parent.
   Transform inheritable_transform_;
 
   // A flag usable during transformation calculates to avoid duplicate work.
   bool dirty_;
 
   Transform transform_;
 
+  VrSurfaceProvider* surface_provider_ = nullptr;
+
   DISALLOW_COPY_AND_ASSIGN(UiElement);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_UI_ELEMENT_H_