Revert of Mustash: Ensure surfaces submitted to Mus by WM and embedders contain Surfaces with embeded content.

services/ui/ws/test_utils.h

Index: services/ui/ws/test_utils.h
diff --git a/services/ui/ws/test_utils.h b/services/ui/ws/test_utils.h
index 808f16f1bf9e61d5d6baca0854aa7c674ba0ae5b..5f5cb302c1972a5debc079f537dd6aa688a5b629 100644
--- a/services/ui/ws/test_utils.h
+++ b/services/ui/ws/test_utils.h
@@ -285,16 +285,13 @@
 // A stub implementation of FrameGeneratorDelegate.
 class TestFrameGeneratorDelegate : public FrameGeneratorDelegate {
  public:
-  TestFrameGeneratorDelegate(ServerWindow* root_window);
+  TestFrameGeneratorDelegate();
   ~TestFrameGeneratorDelegate() override;
 
   // FrameGeneratorDelegate:
-  ServerWindow* GetActiveRootWindow() override;
   bool IsInHighContrastMode() override;
 
  private:
-  ServerWindow* root_window_;
-
   DISALLOW_COPY_AND_ASSIGN(TestFrameGeneratorDelegate);
 };