Make ChromeSigninClient a BrowserContextKeyedService

chrome/browser/signin/signin_manager.h

Index: chrome/browser/signin/signin_manager.h
diff --git a/chrome/browser/signin/signin_manager.h b/chrome/browser/signin/signin_manager.h
index 6c6ef320ba979e84cd1a5d3d79e53112becca0b4..17b20ba0cf84bec22575e74bda2dc63ee729512a 100644
--- a/chrome/browser/signin/signin_manager.h
+++ b/chrome/browser/signin/signin_manager.h
@@ -70,7 +70,7 @@ class SigninManager : public SigninManagerBase,
   // OneClickSigninHelper.
   static const char* kChromeSigninEffectiveSite;
 
-  explicit SigninManager(scoped_ptr<SigninClient> client);
+  explicit SigninManager(SigninClient* client);
   virtual ~SigninManager();
 
   // Returns true if the username is allowed based on the policy string.
@@ -286,7 +286,9 @@ class SigninManager : public SigninManagerBase,
   // but before signin is complete.
   OAuthTokenFetchedCallback oauth_token_fetched_callback_;
 
-  scoped_ptr<SigninClient> client_;
+  // The SigninClient object associated with this object. Must outlive this
+  // object.
+  SigninClient* client_;
 
   // Helper object to listen for changes to signin preferences stored in non-
   // profile-specific local prefs (like kGoogleServicesUsernamePattern).