Second attempt at moving the StackingClient to a property on the RootWindow.

ui/aura/test/aura_test_base.cc

Index: ui/aura/test/aura_test_base.cc
===================================================================
--- ui/aura/test/aura_test_base.cc	(revision 114527)
+++ ui/aura/test/aura_test_base.cc	(working copy)
@@ -9,7 +9,6 @@
 #endif
 
 #include "ui/aura/root_window.h"
-#include "ui/aura/test/test_stacking_client.h"
 
 namespace aura {
 namespace test {
@@ -21,8 +20,6 @@
   OleInitialize(NULL);
 #endif
 
-  // TestStackingClient is owned by the root window.
-  new TestStackingClient();
   RootWindow::GetInstance()->Show();
   RootWindow::GetInstance()->SetHostSize(gfx::Size(600, 600));
 }
@@ -45,11 +42,6 @@
   aura::RootWindow::DeleteInstance();
 }
 
-TestStackingClient* AuraTestBase::GetTestStackingClient() {
-  return static_cast<TestStackingClient*>(
-      aura::RootWindow::GetInstance()->stacking_client());
-}
-
 void AuraTestBase::SetUp() {
   testing::Test::SetUp();
   setup_called_ = true;