mus: Introduce AttachSurface to allow creating Surface prior to OnEmbed

components/mus/public/cpp/tests/test_window_tree.h

Index: components/mus/public/cpp/tests/test_window_tree.h
diff --git a/components/mus/public/cpp/tests/test_window_tree.h b/components/mus/public/cpp/tests/test_window_tree.h
index 67521afa45c44818c63845f7af64a7f26fcd3f63..81b576d70512ef6316cea59e085bff876e447f60 100644
--- a/components/mus/public/cpp/tests/test_window_tree.h
+++ b/components/mus/public/cpp/tests/test_window_tree.h
@@ -41,10 +41,10 @@ class TestWindowTree : public mojom::WindowTree {
                          uint32_t window_id,
                          const mojo::String& name,
                          mojo::Array<uint8_t> value) override;
-  void RequestSurface(uint32_t window_id,
-                      mojom::SurfaceType type,
-                      mojo::InterfaceRequest<mojom::Surface> surface,
-                      mojom::SurfaceClientPtr client) override;
+  void AttachSurface(uint32_t window_id,
+                     mojom::SurfaceType type,
+                     mojo::InterfaceRequest<mojom::Surface> surface,
+                     mojom::SurfaceClientPtr client) override;
   void AddWindow(uint32_t parent,
                  uint32_t child,
                  const AddWindowCallback& callback) override;