Credential passing for WifiManager in Windows

chrome/browser/local_discovery/wifi/credential_getter_win.h

+// Copyright 2014 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 CHROME_BROWSER_LOCAL_DISCOVERY_WIFI_CREDENTIAL_GETTER_WIN_H_
+#define CHROME_BROWSER_LOCAL_DISCOVERY_WIFI_CREDENTIAL_GETTER_WIN_H_
+
+#include "base/message_loop/message_loop_proxy.h"
+#include "content/public/browser/utility_process_host.h"
+#include "content/public/browser/utility_process_host_client.h"
+
+namespace local_discovery {
+namespace wifi {
+
+class CredentialGetterWin : public content::UtilityProcessHostClient {
+ public:
+  typedef base::Callback<void(bool success, const std::string& key)>
+      CredentialsCallback;
+
+  CredentialGetterWin();
+  virtual ~CredentialGetterWin();
+
+  void StartGetCredentials(const std::string& network_guid,
+                           const CredentialsCallback& callback);
+
+  // Used in cases where base::MessageLoopProxy::current() does not exist.
+  void SetCallbackRunner(
+      const scoped_refptr<base::MessageLoopProxy>& callback_runner);

[Vitaly Buka (NO REVIEWS), 2014/06/21 00:33:39]

base::TaskRunner* callback_runner

[stevenjb, 2014/06/23 17:12:20]

Why use TaskRunner here, instead of MesageLoopProxy, which can safely outlive
the message loop? Also, shouldn't const scoped_refptr<>& be preferable to a raw
*?

[Vitaly Buka (NO REVIEWS), 2014/06/23 17:46:27]

Usually Chrome code use TaskRunner or SequencedTaskRunner for similar purpose,
and I believe it's correct.
MesageLoopProxy is TaskRunner, it's subclass of SequencedTaskRunner and
TaskRunner, and TaskRunner is enough here.
It should be up to caller to choose which implementation of TaskRunner to pass
here. Most callers will pass MesageLoopProxy into this method, but decision
about lifecycle should be made by caller, not here.

I had no strong opinion regarding scoped_refptr<> vs pure ptr. My impression is
that pure ptr is usual way to pass RefCounted objects in functions and function
should to create scoped_refptr only if it's going to store pointer after return.


On 2014/06/23 17:12:20, stevenjb wrote:

[Noam Samuel, 2014/06/23 17:55:44]

used const scoped_refptr<base::TaskRunner>&

+
+ private:
+  // UtilityProcessHostClient
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnProcessCrashed(int exit_code) OVERRIDE;
+  virtual void OnProcessLaunchFailed() OVERRIDE;
+
+  // IPC message handlers.
+  void OnGotCredentials(const std::string& key_data, bool success);
+
+  void StartOnIOThread(const std::string& network_guid);
+
+  void PostCallback(bool success, const std::string& key_data);
+
+  CredentialsCallback callback_;
+  scoped_refptr<base::MessageLoopProxy> callback_runner_;

[Vitaly Buka (NO REVIEWS), 2014/06/21 00:33:39]

scoped_refptr<base::TaskRunner>

[Noam Samuel, 2014/06/23 17:55:44]

Done.

+};
+
+}  // namespace wifi
+}  // namespace local_discovery
+
+#endif  // CHROME_BROWSER_LOCAL_DISCOVERY_WIFI_CREDENTIAL_GETTER_WIN_H_