Call CloseClipboard() with anonymous access token.

remoting/host/clipboard_win.cc

Index: remoting/host/clipboard_win.cc
diff --git a/remoting/host/clipboard_win.cc b/remoting/host/clipboard_win.cc
index 21ae6c77395d1e26c030260cd0eab96e72cc6530..ab15b3d5424e20e7053429be6d1bd2f8f60fd08c 100644
--- a/remoting/host/clipboard_win.cc
+++ b/remoting/host/clipboard_win.cc
@@ -32,7 +32,12 @@ class ScopedClipboard {
 
   ~ScopedClipboard() {
     if (opened_) {
+      // CloseClipboard() must be called with anonymous access token. See
+      // crbug.com/441834 .
+      BOOL result = ::ImpersonateAnonymousToken(::GetCurrentThread());
+      CHECK(result);

[Wez, 2014/12/12 19:25:36]

nit: I think it'd be acceptable to just CHECK(ApiCall()) in this case.

[Sergey Ulanov, 2014/12/12 19:34:00]

Side effects inside DCHECKs are often hard to debug. It's not a problem for
CHECK, but still I think it's better to avoid this pattern, e.g. in case this
CHECK gets replaced with DCHECK. 

       ::CloseClipboard();
+      ::RevertToSelf();

[Wez, 2014/12/12 19:25:36]

CHECK this as well?

[Sergey Ulanov, 2014/12/12 19:34:00]

Done.

     }
   }