mus: Implement Window Server Capture

components/mus/view_tree_impl.h

Index: components/mus/view_tree_impl.h
diff --git a/components/mus/view_tree_impl.h b/components/mus/view_tree_impl.h
index 8549585070791a68710945f1bca233e9559f7a94..d14551a195bd5dfd9091f15da9ac876fbd737e01 100644
--- a/components/mus/view_tree_impl.h
+++ b/components/mus/view_tree_impl.h
@@ -114,6 +114,7 @@ class ViewTreeImpl : public mojo::ViewTree, public AccessPolicyDelegate {
                                        bool originated_change);
   void ProcessFocusChanged(const ServerView* old_focused_view,
                            const ServerView* new_focused_view);
+  void ProcessLostCapture(const ServerView* old_captured_view);
 
  private:
   using ViewIdSet = base::hash_set<Id>;
@@ -187,6 +188,8 @@ class ViewTreeImpl : public mojo::ViewTree, public AccessPolicyDelegate {
   void GetViewTree(Id view_id,
                    const mojo::Callback<void(mojo::Array<mojo::ViewDataPtr>)>&
                        callback) override;
+  void SetCapture(Id view_id,
+                  const mojo::Callback<void(bool)>& callback) override;
   void SetViewBounds(Id view_id,
                      mojo::RectPtr bounds,
                      const mojo::Callback<void(bool)>& callback) override;