Palette tool laser prototype.

ash/common/system/chromeos/palette/tools/laser_pointer_view.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 ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_VIEW_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_VIEW_H_
+
+#include <memory>
+
+#include "ash/common/system/chromeos/palette/tools/laser_pointer_points.h"
+#include "base/macros.h"
+#include "ui/events/event.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+
+class LaserPointerModeTestApi;

[jdufault, 2016/08/16 19:33:58]

Please verify that this is needed

[sammiequon, 2016/08/16 23:18:56]

Done.

+// LaserPointerView displays the palette tool laser pointer. It draws the laser
+// as a point which replaces the mouse cursor, as well as a trail of lines to

[jdufault, 2016/08/16 19:33:58]

I'm a bit confused by "It draws the laser as a point"

[sammiequon, 2016/08/16 23:18:56]

Done.

+// help users track the laser.
+class LaserPointerView : public views::View {
+  friend class LaserPointerModeTestApi;

[jdufault, 2016/08/16 19:33:58]

Move friend class decl to right below private:

[sammiequon, 2016/08/16 23:18:56]

Done.

+
+ public:
+  LaserPointerView(base::TimeDelta life_duration);
+  ~LaserPointerView() override;
+
+  void AddNewPoint(const gfx::Point& new_point);
+  void Stop();
+
+ private:
+  // view::View:
+  void OnPaint(gfx::Canvas* canvas) override;
+
+  LaserPointerPoints laser_points_;
+  std::unique_ptr<views::Widget> widget_;
+
+  DISALLOW_COPY_AND_ASSIGN(LaserPointerView);
+};
+
+}  // namespace ash
+
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_VIEW_H_