Introduce some util code for drawing vector assets.

ui/views/controls/throbber.h

 // Copyright (c) 2012 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 UI_VIEWS_CONTROLS_THROBBER_H_
 #define UI_VIEWS_CONTROLS_THROBBER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "ui/views/view.h"
 
-namespace gfx {
-class ImageSkia;
-}
-
 namespace views {
 
 // Throbbers display an animation, usually used as a status indicator.
 
 class VIEWS_EXPORT Throbber : public View {
  public:
   Throbber();
   ~Throbber() override;
 
   // Start and stop the throbber animation.
@@ skipping 11 matching lines @@
   // Specifies whether the throbber is currently animating or not
   bool IsRunning() const;
 
  private:
   base::TimeTicks start_time_;  // Time when Start was called.
   base::RepeatingTimer<Throbber> timer_;  // Used to schedule Run calls.
 
   // Whether or not we should display a checkmark.
   bool checked_;
 
-  // The checkmark image. Will be null until it's used (if ever).
-  const gfx::ImageSkia* checkmark_;
-
   DISALLOW_COPY_AND_ASSIGN(Throbber);
 };
 
 // A SmoothedThrobber is a throbber that is representing potentially short
 // and nonoverlapping bursts of work.  SmoothedThrobber ignores small
 // pauses in the work stops and starts, and only starts its throbber after
 // a small amount of work time has passed.
 class VIEWS_EXPORT SmoothedThrobber : public Throbber {
  public:
   SmoothedThrobber();
@@ skipping 22 matching lines @@
 
   base::OneShotTimer<SmoothedThrobber> start_timer_;
   base::OneShotTimer<SmoothedThrobber> stop_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(SmoothedThrobber);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_THROBBER_H_