mus: Implement Window Server Capture

components/mus/ws/window_manager_access_policy.cc

Index: components/mus/ws/window_manager_access_policy.cc
diff --git a/components/mus/ws/window_manager_access_policy.cc b/components/mus/ws/window_manager_access_policy.cc
index d259ebfcbd934273f7a8078c01649af0eaee5f14..8704f17bbba442bd413c2009a655ec47581c2f60 100644
--- a/components/mus/ws/window_manager_access_policy.cc
+++ b/components/mus/ws/window_manager_access_policy.cc
@@ -103,6 +103,11 @@ bool WindowManagerAccessPolicy::CanSetWindowTextInputState(
   return window->id().connection_id == connection_id_;
 }
 
+bool WindowManagerAccessPolicy::CanSetCapture(
+    const ServerWindow* window) const {
+  return true;

[sky, 2016/01/29 20:47:00]

Actually, you should only allow this if the WM created the window (same as that
on 103). We could allow the wm to grab capture anywhere, but the way the code is
the events would still be routed to the owner.

[jonross, 2016/02/01 18:52:22]

Done.

+}
+
 bool WindowManagerAccessPolicy::CanSetFocus(const ServerWindow* window) const {
   return true;
 }