Fix the content_browsertests everywhere maybe.

ui/aura/client/stacking_client.h

Index: ui/aura/client/stacking_client.h
diff --git a/ui/aura/client/stacking_client.h b/ui/aura/client/stacking_client.h
index 6c0aa5973ffb51a259d7eac621b4cf083326a7c2..89f83eb460193037e7ac68be4e6188476e4a4f65 100644
--- a/ui/aura/client/stacking_client.h
+++ b/ui/aura/client/stacking_client.h
@@ -35,10 +35,6 @@ class AURA_EXPORT StackingClient {
       const gfx::Rect& bounds) = 0;
 };
 
-// Set/Get the default stacking client.
-AURA_EXPORT void SetStackingClient(StackingClient* stacking_client);
-StackingClient* GetStackingClient();
-
 // Set/Get a stacking client for a specific window. Setting the stacking client
 // sets the stacking client on the window's RootWindow, not the window itself.
 // Likewise getting obtains it from the window's RootWindow. If |window| is