Add support for ProxyResolverErrorObserver to ProxyResolverMojo.

net/proxy/proxy_resolver_error_observer_mojo.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 NET_PROXY_PROXY_RESOLVER_ERROR_OBSERVER_MOJO_H_
+#define NET_PROXY_PROXY_RESOLVER_ERROR_OBSERVER_MOJO_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "net/interfaces/proxy_resolver_service.mojom.h"
+#include "net/proxy/proxy_resolver_error_observer.h"
+
+namespace net {
+
+// An implementation of ProxyResolverErrorObserver that forwards errors to an
+// interfaces::ProxyResolverErrorObserver mojo interface.
+class ProxyResolverErrorObserverMojo : public ProxyResolverErrorObserver {
+ public:
+  static scoped_ptr<ProxyResolverErrorObserver> Create(
+      interfaces::ProxyResolverErrorObserverPtr error_observer);
+
+  void OnPACScriptError(int line_number, const base::string16& error) override;
+
+ private:
+  explicit ProxyResolverErrorObserverMojo(
+      interfaces::ProxyResolverErrorObserverPtr error_observer);
+  ~ProxyResolverErrorObserverMojo() override;
+
+  // |error_observer_| may only be accessed when running on |task_runner_|.
+  interfaces::ProxyResolverErrorObserverPtr error_observer_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  // Creating a new WeakPtr is only valid on the original thread, but copying an
+  // existing WeakPtr is valid on any thread so keep |weak_this_| ready to copy.
+  base::WeakPtr<ProxyResolverErrorObserverMojo> weak_this_;
+  base::WeakPtrFactory<ProxyResolverErrorObserverMojo> weak_factory_;
+};
+
+}  // namespace net
+
+#endif  // NET_PROXY_PROXY_RESOLVER_ERROR_OBSERVER_MOJO_H_