MacViews: support backgrounds for selected rows

ui/views/style/platform_style.h

Index: ui/views/style/platform_style.h
diff --git a/ui/views/style/platform_style.h b/ui/views/style/platform_style.h
index 8534aa276355da0e534c82c363f2aa1d5f5e23c6..70f05442b5c0c36943d027c3e15f79c558021e26 100644
--- a/ui/views/style/platform_style.h
+++ b/ui/views/style/platform_style.h
@@ -42,6 +42,10 @@ class VIEWS_EXPORT PlatformStyle {
   // the left or right end of the text from the cursor, respectively.
   static const bool kTextfieldDragVerticallyDragsToEnd;
 
+  // Whether selecting a row in a TreeView selects the entire row or only the
+  // label for that row.
+  static const bool kTreeViewSelectsEntireRow;

[sky, 2016/06/16 17:34:39]

nit: I think kTreeViewSelectionPaintsEntireRow makes it clearer what this
controls.

[Elly Fong-Jones, 2016/06/23 19:47:13]

Done.

+
   // Creates an ImageSkia containing the image to use for the combobox arrow.
   // The |is_enabled| argument is true if the control the arrow is for is
   // enabled, and false if the control is disabled. The |style| argument is the