Handle multiple signin_internal_uis by using a linked_ptr.

Fixes an issue where chrome://signin-internals page is opened multiple times, and the scoped_ptr was getting de-allocated by the first object. Moving to a linked_ptr for more robust reference counting.

BUG=416802

Review URL: https://codereview.chromium.org/602773002

Cr-Commit-Position: refs/heads/master@{#296932}

chrome/browser/ui/webui/signin_internals_ui.cc

@@ -79,13 +79,13 @@ bool SignInInternalsUI::OverrideHandleWebUIMessage(
 }
 
 void SignInInternalsUI::OnSigninStateChanged(
-    scoped_ptr<base::DictionaryValue> info) {
+    const base::DictionaryValue* info) {
   web_ui()->CallJavascriptFunction(
       "chrome.signin.onSigninInfoChanged.fire", *info);
 }
 
 void SignInInternalsUI::OnCookieAccountsFetched(
-    scoped_ptr<base::DictionaryValue> info) {
+    const base::DictionaryValue* info) {
   web_ui()->CallJavascriptFunction(
       "chrome.signin.onCookieAccountsFetched.fire", *info);
 }

chrome/browser/ui/webui/signin_internals_ui.h

@@ -7,7 +7,6 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "components/signin/core/browser/about_signin_internals.h"
 #include "content/public/browser/web_ui_controller.h"
@@ -26,12 +25,11 @@ class SignInInternalsUI : public content::WebUIController,
                                           const base::ListValue& args) OVERRIDE;
 
   // AboutSigninInternals::Observer::OnSigninStateChanged implementation.
-  virtual void OnSigninStateChanged(
-      scoped_ptr<base::DictionaryValue> info) OVERRIDE;
+  virtual void OnSigninStateChanged(const base::DictionaryValue* info) OVERRIDE;
 
   // Notification that the cookie accounts are ready to be displayed.
   virtual void OnCookieAccountsFetched(
-      scoped_ptr<base::DictionaryValue> info) OVERRIDE;
+      const base::DictionaryValue* info) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SignInInternalsUI);

components/signin/core/browser/about_signin_internals.cc

@@ -220,10 +220,11 @@ void AboutSigninInternals::Shutdown() {
 }
 
 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() {
@@ -295,7 +296,8 @@ void AboutSigninInternals::OnCookieChanged(
 }
 
 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()));
@@ -324,9 +326,9 @@ void AboutSigninInternals::OnListAccountsFailure(
 
 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,
@@ -340,7 +342,7 @@ void AboutSigninInternals::OnListAccountsComplete(
   // 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(

components/signin/core/browser/about_signin_internals.h

@@ -8,6 +8,7 @@
 #include <map>
 #include <string>
 
+#include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/values.h"
@@ -39,12 +40,10 @@ class AboutSigninInternals
    public:
     // |info| will contain the dictionary of signin_status_ values as indicated
     // in the comments for GetSigninStatus() below.
-    virtual void OnSigninStateChanged(
-        scoped_ptr<base::DictionaryValue> info) = 0;
+    virtual void OnSigninStateChanged(const base::DictionaryValue* info) = 0;
 
     // Notification that the cookie accounts are ready to be displayed.
-    virtual void OnCookieAccountsFetched(
-        scoped_ptr<base::DictionaryValue> info) = 0;
+    virtual void OnCookieAccountsFetched(const base::DictionaryValue* info) = 0;
   };
 
   AboutSigninInternals(ProfileOAuth2TokenService* token_service,