Desktop aura: Break aura::Window::SetParent in two.

ui/aura/test/aura_test_base.h

Index: ui/aura/test/aura_test_base.h
diff --git a/ui/aura/test/aura_test_base.h b/ui/aura/test/aura_test_base.h
index 2b8990a96f9423dad5df3b42f8c6424a0fe4ec7a..c7daec346ffee7044e6e62edce83fbdf44a81079 100644
--- a/ui/aura/test/aura_test_base.h
+++ b/ui/aura/test/aura_test_base.h
@@ -13,6 +13,7 @@
 
 namespace aura {
 class RootWindow;
+class Window;
 namespace test {
 
 // A base class for aura unit tests.
@@ -26,6 +27,12 @@ class AuraTestBase : public testing::Test {
   virtual void SetUp() OVERRIDE;
   virtual void TearDown() OVERRIDE;
 
+  // Creates a transient window that is transient to |parent|.
+  aura::Window* CreateTransientChild(int id, aura::Window* parent);
+
+  // Attach |window| to the current shell's root window.
+  void SetDefaultParentByPrimaryRootWindow(aura::Window* window);
+
  protected:
   void RunAllPendingInMessageLoop();