Adding drawable to CRD andorid and iOS gl rendering pipeline.

remoting/client/display/gl_cursor_feedback.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 REMOTING_CLIENT_DISPLAY_GL_CURSOR_FEEDBACK_H_
 #define REMOTING_CLIENT_DISPLAY_GL_CURSOR_FEEDBACK_H_
 
-#include <stdint.h>
+#include <cstdint>
 
 #include <memory>
 
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "base/time/time.h"
+#include "remoting/client/display/drawable.h"
 
 namespace remoting {
 
-class GlCanvas;
+class Canvas;
 class GlRenderLayer;
 
 // This class draws the cursor feedback on the canvas.
-class GlCursorFeedback {
+class GlCursorFeedback : public Drawable {
  public:
   GlCursorFeedback();
-  ~GlCursorFeedback();
-
-  // Sets the canvas on which the cursor feedback will be drawn. Resumes the
-  // feedback texture to the context of the new canvas.
-  // If |canvas| is nullptr, nothing will happen when calling Draw().
-  void SetCanvas(GlCanvas* canvas);
+  ~GlCursorFeedback() override;
 
   void StartAnimation(float x, float y, float diameter);
 
-  // Returns true if animation is not finished, false otherwise. Does nothing
-  // if the animation has stopped.
-  bool Draw();
+  // Drawable implementation.
+  void SetCanvas(base::WeakPtr<Canvas> canvas) override;
+  bool Draw() override;
+  int GetZIndex() override;
+  base::WeakPtr<Drawable> GetWeakPtr() override;
 
  private:
   std::unique_ptr<GlRenderLayer> layer_;
   float max_diameter_ = 0;
   float cursor_x_ = 0;
   float cursor_y_ = 0;
   base::TimeTicks animation_start_time_;
 
+  base::ThreadChecker thread_checker_;
+  base::WeakPtrFactory<Drawable> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(GlCursorFeedback);
 };
 
 }  // namespace remoting
 #endif  // REMOTING_CLIENT_DISPLAY_GL_CURSOR_FEEDBACK_H_