Make panel window's header color customizable in Ash.

ash/wm/panels/panel_frame_view.cc

Index: ash/wm/panels/panel_frame_view.cc
diff --git a/ash/wm/panels/panel_frame_view.cc b/ash/wm/panels/panel_frame_view.cc
index 733af9adfbd43e1fb57901a72587359d934b31d3..87e6f3479571b8316e6792390c225d4c8492ac19 100644
--- a/ash/wm/panels/panel_frame_view.cc
+++ b/ash/wm/panels/panel_frame_view.cc
@@ -32,6 +32,11 @@ PanelFrameView::PanelFrameView(views::Widget* frame, FrameType frame_type)
 PanelFrameView::~PanelFrameView() {
 }
 
+void PanelFrameView::SetFrameColors(SkColor active_frame_color,
+                                    SkColor inactive_frame_color) {
+  header_painter_->SetFrameColors(active_frame_color, inactive_frame_color);
+}
+
 const char* PanelFrameView::GetClassName() const {
   return kViewClassName;
 }