MacViews: draw combobox arrow backgrounds

ui/views/style/mac/combobox_background_mac.h

Index: ui/views/style/mac/combobox_background_mac.h
diff --git a/ui/views/style/mac/combobox_background_mac.h b/ui/views/style/mac/combobox_background_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..80090c834f16c1b2d431320d16d9e5822c9f6994
--- /dev/null
+++ b/ui/views/style/mac/combobox_background_mac.h
@@ -0,0 +1,26 @@
+// 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 UI_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_
+#define UI_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_
+
+#include "ui/views/background.h"
+
+namespace gfx {
+class Canvas;
+}  // namespace gfx

[tapted, 2016/03/22 23:04:33]

nit: comments don't usually get put on the namespace blocks used for forward
decs

[Elly Fong-Jones, 2016/03/23 18:07:44]

Done.

+
+namespace views {
+
+class ComboboxBackgroundMac : public Background {

[tapted, 2016/03/22 23:04:32]

needs a brief comment

[Elly Fong-Jones, 2016/03/23 18:07:44]

Done.

+ public:
+  ComboboxBackgroundMac() {}

[tapted, 2016/03/22 23:04:32]

nit: these should be defined in the .cc  [there's usually a clang chromium-style
warning about cases where the destructor is non-trivial - technically the
destructor *is* trivial, but the compiler shouldn't know that since Background's
destructor is in its .cc]

[Elly Fong-Jones, 2016/03/23 18:07:44]

Done.

+  ~ComboboxBackgroundMac() override {}
+
+  void Paint(gfx::Canvas* canvas, View* view) const override;

[tapted, 2016/03/22 23:04:33]

nit: // Background:

[Elly Fong-Jones, 2016/03/23 18:07:44]

Done.

+};

[tapted, 2016/03/22 23:04:32]

nit: private: DISALLOW_COPY_AND_ASSIGN

[Elly Fong-Jones, 2016/03/23 18:07:44]

Done.

+
+}  // namespace views
+
+#endif  // UI_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_