[Proximity Auth] Create one ProximityAuthClient per profile, rather than one global one.

chrome/browser/signin/chrome_proximity_auth_client_factory.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 CHROME_BROWSER_SIGNIN_CHROME_PROXIMITY_AUTH_CLIENT_FACTORY_H_
+#define CHROME_BROWSER_SIGNIN_CHROME_PROXIMITY_AUTH_CLIENT_FACTORY_H_
+
+#include "base/memory/singleton.h"
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+
+class ChromeProximityAuthClient;
+class KeyedService;
+class Profile;
+
+namespace content {
+class BrowserContext;
+}
+
+// Singleton that owns all |ChromeProximityAuthClient| instances and associates
+// them with profiles. Listens for each profile's destruction notification and

[Mike Lerman, 2015/06/26 13:09:51]

I don't see where you react to the Profile destruction, and the KeyedService
doesn't override Shutdown(). 

[Ilya Sherman, 2015/06/27 08:18:00]

Whoops, you can see which class I copy/pasta'd :P

Removed this whole file, so no longer relevant.  Good catch though =)

+// cleans up the associated SigninManager.
+class ChromeProximityAuthClientFactory
+    : public BrowserContextKeyedServiceFactory {
+ public:
+  // Returns an instance of the |ChromeProximityAuthClientFactory| singleton.
+  static ChromeProximityAuthClientFactory* GetInstance();
+
+  // Returns the |ChromeProximityAuthClient| for the given |profile|, creating
+  // it if necessary.
+  static ChromeProximityAuthClient* GetForProfile(Profile* profile);
+
+ private:
+  friend struct DefaultSingletonTraits<ChromeProximityAuthClientFactory>;
+
+  ChromeProximityAuthClientFactory();
+  ~ChromeProximityAuthClientFactory() override;
+
+  // BrowserContextKeyedServiceFactory:
+  KeyedService* BuildServiceInstanceFor(
+      content::BrowserContext* context) const override;
+};
+
+#endif  // CHROME_BROWSER_SIGNIN_CHROME_PROXIMITY_AUTH_CLIENT_FACTORY_H_