aura: Make aura::TooltipClient completely static?

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 997886291df8ce2226855871d58e5633dc740e03..6529a5990428b2daacfb3e85029f6645597e82e4 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -273,12 +273,7 @@ void RenderWidgetHostViewAura::Destroy() {
 
 void RenderWidgetHostViewAura::SetTooltipText(const string16& tooltip_text) {
   tooltip_ = tooltip_text;
-  void* property = aura::Desktop::GetInstance()->GetProperty(
-      aura::kDesktopTooltipClientKey);
-  if (property) {
-    aura::TooltipClient* tc = static_cast<aura::TooltipClient*>(property);
-    tc->UpdateTooltip(window_);
-  }
+  aura::TooltipClient::UpdateTooltip(window_);
 }
 
 BackingStore* RenderWidgetHostViewAura::AllocBackingStore(