Aura: Make compositor_unittests work with --ui-enable-threaded-compositing

ui/compositor/test/test_compositor_host_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/compositor/test/test_compositor_host.h"
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/win/window_impl.h"
 #include "ui/compositor/compositor.h"
@@ skipping 17 matching lines @@
   // Overridden from TestCompositorHost:
   virtual void Show() OVERRIDE {
     ShowWindow(hwnd(), SW_SHOWNORMAL);
   }
   virtual ui::Compositor* GetCompositor() OVERRIDE {
     return compositor_.get();
   }
 
   // Overridden from CompositorDelegate:
   virtual void ScheduleDraw() OVERRIDE {
+    DCHECK(!ui::Compositor::WasInitializedWithThread());
     RECT rect;
     ::GetClientRect(hwnd(), &rect);
     InvalidateRect(hwnd(), &rect, FALSE);
   }
 
  private:
   BEGIN_MSG_MAP_EX(TestCompositorHostWin)
     MSG_WM_PAINT(OnPaint)
   END_MSG_MAP()
 
@@ skipping 11 matching lines @@
   scoped_ptr<ui::Compositor> compositor_;
 
   DISALLOW_COPY_AND_ASSIGN(TestCompositorHostWin);
 };
 
 TestCompositorHost* TestCompositorHost::Create(const gfx::Rect& bounds) {
   return new TestCompositorHostWin(bounds);
 }
 
 }  // namespace ui