Update Windows UI on system color changes.

ui/views/widget/root_view.cc

Index: ui/views/widget/root_view.cc
diff --git a/ui/views/widget/root_view.cc b/ui/views/widget/root_view.cc
index b103943cd13e3bd81f2f5af4ac652c1a13e47c4e..1638fe24162a25c492afe7225c05079bbb7b29ff 100644
--- a/ui/views/widget/root_view.cc
+++ b/ui/views/widget/root_view.cc
@@ -15,6 +15,7 @@
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/canvas.h"
+#include "ui/native_theme/native_theme.h"
 #include "ui/views/focus/view_storage.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view_targeter.h"
@@ -119,9 +120,11 @@ RootView::RootView(Widget* widget)
       old_dispatch_target_(NULL) {
   AddPreTargetHandler(pre_dispatch_handler_.get());
   SetEventTargeter(scoped_ptr<ui::EventTargeter>(new ViewTargeter()));
+  GetNativeTheme()->AddObserver(this);

[Evan Stade, 2014/04/22 17:43:44]

ScopedObserver?

[msw, 2014/04/22 19:48:58]

Eh, it doesn't seem worthwhile to add a class member to handle one
RemoveObserver call; what do you think?

[Evan Stade, 2014/04/22 21:09:18]

I always prefer scoping variables over doing stuff manually, which is error
prone.

[msw, 2014/04/23 00:34:04]

Done (in Widget).

 }
 
 RootView::~RootView() {
+  GetNativeTheme()->RemoveObserver(this);
   // If we have children remove them explicitly so to make sure a remove
   // notification is sent for each one of them.
   if (has_children())
@@ -502,6 +505,10 @@ void RootView::UpdateParentLayer() {
     ReparentLayer(gfx::Vector2d(GetMirroredX(), y()), widget_->GetLayer());
 }
 
+void RootView::OnNativeThemeChange() {
+  PropagateNativeThemeChanged(GetNativeTheme());
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // RootView, protected: