Implemented system tray UI for new account management.

ash/system/user/user_accounts_delegate.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 ASH_SYSTEM_USER_USER_ACCOUNTS_DELEGATE_H_
+#define ASH_SYSTEM_USER_USER_ACCOUNTS_DELEGATE_H_
+
+#include <string>
+#include <vector>
+
+#include "ash/ash_export.h"
+#include "base/macros.h"
+#include "base/observer_list.h"
+
+namespace ash {
+namespace tray {
+
+class ASH_EXPORT UserAccountsDelegate {
+ public:
+  class Observer {
+   public:
+    Observer() {}

[oshima, 2014/04/02 00:14:14]

optional: I think you can omit ctor in this case. it's up to you.

+    virtual ~Observer() {}
+
+    // Called when the account list of user has been changed.
+    virtual void AccountListChanged() = 0;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Observer);
+  };
+
+  UserAccountsDelegate();
+  virtual ~UserAccountsDelegate();
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Returns the user's primary account as a canonicalized email address.
+  virtual std::string GetPrimaryAccount() = 0;

[oshima, 2014/03/31 23:07:52]

Q: Is std::string what the multi-login uses as an account id in chrome?

We have too many ways to identify a user and I wonder if we can just use
content::BrowsrContext instead.

[dzhioev (left Google), 2014/04/01 17:25:02]

Yes, TokenService uses std::string as account ID. See
https://code.google.com/p/chromium/codesearch#chromium/src/components/signin/...
Isn't BrowserContext equivalent to Profile? If so, that will not gonna work,
because we have one-to-one correspondence between users and their profiles.
Account is not the same thing as user. One user can have several accounts.

[oshima, 2014/04/02 00:14:14]

That's only true in browser process and they do not have to be equivalent,
(like appshell uses BrowserContext as is).
In any case, if this is what the underlying system is using, I'm fine.

+
+  // Returns a list of the user's secondary accounts in form of canonicalized
+  // email addresses.
+  virtual std::vector<std::string> GetSecondaryAccountsList() = 0;
+
+  // Returns display name for given |account_id|. It has form of email but could
+  // be uncanonical, e.g. account "test-user@gmail.com" could have display
+  // name "Test-user+AfterPlus@gmail.com".
+  virtual std::string GetAccountDisplayName(const std::string& account_id) = 0;

[oshima, 2014/03/31 23:07:52]

shouldn't this be string16?

[dzhioev (left Google), 2014/04/01 17:25:02]

Probably not. For primary account it will be "display email" which is latin. For
secondary accounts DisplayName will be equal to account_id.

[oshima, 2014/04/02 00:14:14]

I see. It's unfortunate that we're using different representation from
multi-profile,
but may be this is to make the difference more obvious.

+
+  // Deletes given |account_id| from the list of user's account. Passing
+  // |account_id| that is not from list is no-op.
+  virtual void DeleteAccount(const std::string& account_id) = 0;
+
+  // Launches a dialog which lets the user add a new account.
+  virtual void LaunchAddAccountDialog() = 0;
+
+ protected:
+  void NotifyAccountListChanged();
+
+ private:
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserAccountsDelegate);
+};
+
+}  // namespace tray
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_USER_USER_ACCOUNTS_DELEGATE_H_