MenuButton: support Mac look & feel

ui/gfx/scoped_canvas.h

Index: ui/gfx/scoped_canvas.h
diff --git a/ui/gfx/scoped_canvas.h b/ui/gfx/scoped_canvas.h
index 4a260bf93c3622b78892628667e839c4d2a21632..8517040e810ad50fe64ce74336c9a272fa8b602e 100644
--- a/ui/gfx/scoped_canvas.h
+++ b/ui/gfx/scoped_canvas.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/geometry/rect.h"

[tapted, 2016/04/22 13:46:52]

forward-declare?

[Elly Fong-Jones, 2016/04/25 14:30:50]

Done.

 
 namespace gfx {
 
@@ -28,6 +29,21 @@ class ScopedCanvas {
   DISALLOW_COPY_AND_ASSIGN(ScopedCanvas);
 };
 
+// Saves the drawing state, and applies an RTL transform for the supplied rect
+// if the UI is in RTL layout. The resulting transform is such that anything
+// drawn inside the supplied rect will be flipped RTL.

[tapted, 2016/04/22 13:46:52]

nit: replace `flipped RTL` with `horizontally flipped`.

(to me at least, "RTL" seems like a concept of it's own, rather than something
that should be spoken "right to left")

[Elly Fong-Jones, 2016/04/25 14:30:50]

Done.

+

[tapted, 2016/04/22 13:46:52]

nit: remove blank line

[Elly Fong-Jones, 2016/04/25 14:30:50]

Done.

+class ScopedRTLFlipCanvas {
+ public:
+  ScopedRTLFlipCanvas(gfx::Canvas* canvas, gfx::Rect rect);

[tapted, 2016/04/22 13:46:52]

nit: const-ref on `rect`

[Elly Fong-Jones, 2016/04/25 14:30:50]

Done.

+  ~ScopedRTLFlipCanvas() {}
+
+ private:
+  ScopedCanvas canvas_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedRTLFlipCanvas);
+};
+
 }  // namespace gfx
 
 #endif  // UI_GFX_SCOPED_CANVAS_H_