Use webrtc::MouseCursorMonitor for cursor shapes

remoting/host/chromoting_messages.h

Index: remoting/host/chromoting_messages.h
diff --git a/remoting/host/chromoting_messages.h b/remoting/host/chromoting_messages.h
index e56b0f3a19d54c82c6b64b30271da24a64fd4f9d..6ad72cddee19cff3f4ffddabfe37e0700442308c 100644
--- a/remoting/host/chromoting_messages.h
+++ b/remoting/host/chromoting_messages.h
@@ -138,12 +138,6 @@ IPC_MESSAGE_CONTROL3(ChromotingDesktopNetworkMsg_CreateSharedBuffer,
 IPC_MESSAGE_CONTROL1(ChromotingDesktopNetworkMsg_ReleaseSharedBuffer,
                      int /* id */)
 
-IPC_STRUCT_TRAITS_BEGIN(webrtc::MouseCursorShape)
-  IPC_STRUCT_TRAITS_MEMBER(size)
-  IPC_STRUCT_TRAITS_MEMBER(hotspot)
-  IPC_STRUCT_TRAITS_MEMBER(data)
-IPC_STRUCT_TRAITS_END()
-
 // Serialized webrtc::DesktopFrame.
 IPC_STRUCT_BEGIN(SerializedDesktopFrame)
   // ID of the shared memory buffer containing the pixels.
@@ -173,8 +167,11 @@ IPC_MESSAGE_CONTROL1(ChromotingDesktopNetworkMsg_CaptureCompleted,
                      SerializedDesktopFrame /* frame */ )
 
 // Carries a cursor share update from the desktop session agent to the client.
-IPC_MESSAGE_CONTROL1(ChromotingDesktopNetworkMsg_CursorShapeChanged,
-                     webrtc::MouseCursorShape /* cursor_shape */ )
+// N.B. |webrtc::MouseCursor| is immutable which makes it non-serializable by
+// the IPC library. We work around this limitation by passing a scoped_ptr
+// instead. |cursor| must be non-NULL.
+IPC_MESSAGE_CONTROL1(ChromotingDesktopNetworkMsg_MouseCursor,
+                     scoped_ptr<webrtc::MouseCursor> /* cursor */ )
 
 // Carries a clipboard event from the desktop session agent to the client.
 // |serialized_event| is a serialized protocol::ClipboardEvent.