mus: Implement Window Server Capture

components/mus/ws/window_tree_unittest.cc

Index: components/mus/ws/window_tree_unittest.cc
diff --git a/components/mus/ws/window_tree_unittest.cc b/components/mus/ws/window_tree_unittest.cc
index 6170173750063556c9d446edecb23183b9ac1f6f..0a0df719bb9414bd23b75f774f97d183adff4fb2 100644
--- a/components/mus/ws/window_tree_unittest.cc
+++ b/components/mus/ws/window_tree_unittest.cc
@@ -121,6 +121,7 @@ class TestWindowTreeClient : public mus::mojom::WindowTreeClient {
     tracker_.OnEmbeddedAppDisconnected(window);
   }
   void OnUnembed(Id window_id) override { tracker_.OnUnembed(window_id); }
+  void OnLostCapture(Id window_id) override {}
   void OnTopLevelCreated(uint32_t change_id,
                          mojom::WindowDataPtr data) override {
     tracker_.OnTopLevelCreated(change_id, std::move(data));
@@ -312,6 +313,8 @@ class TestDisplayManager : public DisplayManager {
                      const gfx::Rect& bounds) override {}
   void SetViewportSize(const gfx::Size& size) override {}
   void SetTitle(const base::string16& title) override {}
+  void SetCapture() override {}
+  void ReleaseCapture() override {}
   void SetCursorById(int32_t cursor) override { *cursor_id_storage_ = cursor; }
   const mojom::ViewportMetrics& GetViewportMetrics() override {
     return display_metrices_;