Handle multiple signin_internal_uis by using a linked_ptr

components/signin/core/browser/about_signin_internals.cc

 // Copyright (c) 2012 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.
 
 #include "components/signin/core/browser/about_signin_internals.h"
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/hash.h"
 #include "base/i18n/time_formatting.h"
@@ skipping 202 matching lines @@
      base::Unretained(this)));
 }
 
 void AboutSigninInternals::Shutdown() {
   signin_manager_->RemoveSigninDiagnosticsObserver(this);
   token_service_->RemoveDiagnosticsObserver(this);
   cookie_changed_subscription_.reset();
 }
 
 void AboutSigninInternals::NotifyObservers() {
+  scoped_ptr<base::DictionaryValue> signin_status_value =
+      signin_status_.ToValue(client_->GetProductVersion());
   FOR_EACH_OBSERVER(AboutSigninInternals::Observer,
                     signin_observers_,
-                    OnSigninStateChanged(
-                        signin_status_.ToValue(client_->GetProductVersion())));
+                    OnSigninStateChanged(signin_status_value.get()));
 }
 
 scoped_ptr<base::DictionaryValue> AboutSigninInternals::GetSigninStatus() {
   return signin_status_.ToValue(client_->GetProductVersion()).Pass();
 }
 
 void AboutSigninInternals::OnAccessTokenRequested(
     const std::string& account_id,
     const std::string& consumer_id,
     const OAuth2TokenService::ScopeSet& scopes) {
@@ skipping 51 matching lines @@
     const net::CanonicalCookie* cookie) {
   if (cookie->Name() == "LSID" &&
       cookie->Domain() == GaiaUrls::GetInstance()->gaia_url().host() &&
       cookie->IsSecure() &&
       cookie->IsHttpOnly()) {
     GetCookieAccountsAsync();
   }
 }
 
 void AboutSigninInternals::GetCookieAccountsAsync() {
-  if (!gaia_fetcher_) {
+  // Don't bother calling /ListAccounts if no one will observe the response.
+  if (!gaia_fetcher_ && signin_observers_.might_have_observers()) {
     // There is no list account request in flight.
     gaia_fetcher_.reset(new GaiaAuthFetcher(
         this, GaiaConstants::kChromeSource, client_->GetURLRequestContext()));
     gaia_fetcher_->StartListAccounts();
   }
 }
 
 void AboutSigninInternals::OnListAccountsSuccess(const std::string& data) {
   gaia_fetcher_.reset();
 
   // Get account information from response data.
   std::vector<std::pair<std::string, bool> > gaia_accounts;
   bool valid_json = gaia::ParseListAccountsData(data, &gaia_accounts);
   if (!valid_json) {
     VLOG(1) << "AboutSigninInternals::OnListAccountsSuccess: parsing error";
   } else {
     OnListAccountsComplete(gaia_accounts);
   }
 }
 
 void AboutSigninInternals::OnListAccountsFailure(
     const GoogleServiceAuthError& error) {
   gaia_fetcher_.reset();
   VLOG(1) << "AboutSigninInternals::OnListAccountsFailure:" << error.ToString();
 }
 
 void AboutSigninInternals::OnListAccountsComplete(
     std::vector<std::pair<std::string, bool> >& gaia_accounts) {
-  scoped_ptr<base::DictionaryValue> signin_status(new base::DictionaryValue());
+  base::DictionaryValue signin_status;
   base::ListValue* cookie_info = new base::ListValue();
-  signin_status->Set("cookie_info", cookie_info);
+  signin_status.Set("cookie_info", cookie_info);
 
   for (size_t i = 0; i < gaia_accounts.size(); ++i) {
     AddCookieEntry(cookie_info,
                    gaia_accounts[i].first,
                    gaia_accounts[i].second ? "Valid" : "Invalid");
   }
 
   if (gaia_accounts.size() == 0)
     AddCookieEntry(cookie_info, "No Accounts Present.", "");
 
   // Update the observers that the cookie's accounts are updated.
   FOR_EACH_OBSERVER(AboutSigninInternals::Observer,
                     signin_observers_,
-                    OnCookieAccountsFetched(signin_status.Pass()));
+                    OnCookieAccountsFetched(&signin_status));
 }
 
 AboutSigninInternals::TokenInfo::TokenInfo(
     const std::string& consumer_id,
     const OAuth2TokenService::ScopeSet& scopes)
     : consumer_id(consumer_id),
       scopes(scopes),
       request_time(base::Time::Now()),
       error(GoogleServiceAuthError::AuthErrorNone()),
       removed_(false) {}
@@ skipping 127 matching lines @@
     std::sort(it->second.begin(), it->second.end(), TokenInfo::LessThan);
     const std::vector<TokenInfo*>& tokens = it->second;
     for (size_t i = 0; i < tokens.size(); ++i) {
       base::DictionaryValue* token_info = tokens[i]->ToValue();
       token_details->Append(token_info);
     }
   }
 
   return signin_status.Pass();
 }