mus: Implement Window Server Capture

components/mus/test_change_tracker.cc

Index: components/mus/test_change_tracker.cc
diff --git a/components/mus/test_change_tracker.cc b/components/mus/test_change_tracker.cc
index 72dd0bc475a42d043c38f57bdb823c1b81245f32..09f9a389b748d556a22372dbf2008be2d1ac23d8 100644
--- a/components/mus/test_change_tracker.cc
+++ b/components/mus/test_change_tracker.cc
@@ -43,6 +43,10 @@ std::string ChangeToDescription1(const Change& change) {
     case CHANGE_TYPE_UNEMBED:
       return "OnUnembed";
 
+    case CHANGE_TYPE_LOST_CAPTURE:
+      return base::StringPrintf("OnLostCapture view=%s",
+                                ViewIdToString(change.view_id).c_str());
+
     case CHANGE_TYPE_NODE_BOUNDS_CHANGED:
       return base::StringPrintf(
           "BoundsChanged view=%s old_bounds=%s new_bounds=%s",
@@ -210,6 +214,13 @@ void TestChangeTracker::OnUnembed() {
   AddChange(change);
 }
 
+void TestChangeTracker::OnLostCapture(Id view_id) {
+  Change change;
+  change.type = CHANGE_TYPE_LOST_CAPTURE;
+  change.view_id = view_id;
+  AddChange(change);
+}
+
 void TestChangeTracker::OnViewViewportMetricsChanged(
     mojo::ViewportMetricsPtr old_metrics,
     mojo::ViewportMetricsPtr new_metrics) {