Use OnceCallback for Mojo binding connection error handlers.

mojo/public/cpp/bindings/associated_interface_ptr.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 118 matching lines @@
   }
 
   // Indicates whether an error has been encountered. If true, method calls made
   // on this interface will be dropped (and may already have been dropped).
   bool encountered_error() const { return internal_state_.encountered_error(); }
 
   // Registers a handler to receive error notifications.
   //
   // This method may only be called after the AssociatedInterfacePtr has been
   // bound.
-  void set_connection_error_handler(const base::Closure& error_handler) {
-    internal_state_.set_connection_error_handler(error_handler);
+  void set_connection_error_handler(base::OnceClosure error_handler) {
+    internal_state_.set_connection_error_handler(std::move(error_handler));
   }
 
   void set_connection_error_with_reason_handler(
-      const ConnectionErrorWithReasonCallback& error_handler) {
-    internal_state_.set_connection_error_with_reason_handler(error_handler);
+      ConnectionErrorWithReasonCallback error_handler) {
+    internal_state_.set_connection_error_with_reason_handler(
+        std::move(error_handler));
   }
 
   // Unbinds and returns the associated interface pointer information which
   // could be used to setup an AssociatedInterfacePtr again. This method may be
   // used to move the proxy to a different thread.
   //
   // It is an error to call PassInterface() while there are pending responses.
   // TODO: fix this restriction, it's not always obvious when there is a
   // pending response.
   AssociatedInterfacePtrInfo<Interface> PassInterface() {
@@ skipping 113 matching lines @@
 // |handle| is supposed to be the request of an associated interface. This
 // method associates the interface with a dedicated, disconnected message pipe.
 // That way, the corresponding associated interface pointer of |handle| can
 // safely make calls (although those calls are silently dropped).
 MOJO_CPP_BINDINGS_EXPORT void GetIsolatedInterface(
     ScopedInterfaceEndpointHandle handle);
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_H_