Add context to gfx::Screen calls in support of simultaneous desktop+ash

ui/views/controls/button/custom_button.cc

Index: ui/views/controls/button/custom_button.cc
diff --git a/ui/views/controls/button/custom_button.cc b/ui/views/controls/button/custom_button.cc
index 612ddd02dff6de60c5e3aaecf9778564ce795d71..6e981413a5a5861eaeddfd712ed8afa9d76b42f9 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -74,7 +74,8 @@ bool CustomButton::IsMouseHovered() const {
   if (!GetWidget())
     return false;
 
-  gfx::Point cursor_pos(gfx::Screen::GetCursorScreenPoint());
+  gfx::Point cursor_pos(gfx::Screen::GetScreenFor(
+      GetWidget()->GetNativeView())->GetCursorScreenPoint());
   ConvertPointToTarget(NULL, this, &cursor_pos);
   return HitTestPoint(cursor_pos);
 }