mus: Implement Window Server Capture

components/mus/ws/display_manager.h

Index: components/mus/ws/display_manager.h
diff --git a/components/mus/ws/display_manager.h b/components/mus/ws/display_manager.h
index be2c3130c57e5d1733f7056a2d5a792e778b2ead..b23b8db72917eee0e50d589c5e24372adc53728e 100644
--- a/components/mus/ws/display_manager.h
+++ b/components/mus/ws/display_manager.h
@@ -75,6 +75,10 @@ class DisplayManager {
 
   virtual void SetTitle(const base::string16& title) = 0;
 
+  virtual void SetCapture() = 0;
+
+  virtual void ReleaseCapture() = 0;
+
   virtual void SetCursorById(int32_t cursor) = 0;
 
   virtual mojom::Rotation GetRotation() = 0;
@@ -114,6 +118,8 @@ class DefaultDisplayManager : 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;
   const mojom::ViewportMetrics& GetViewportMetrics() override;
   mojom::Rotation GetRotation() override;