Make ProfileSigninConfirmationHelper delete itself instead of being refcounted.

chrome/browser/ui/sync/profile_signin_confirmation_helper.cc

Index: chrome/browser/ui/sync/profile_signin_confirmation_helper.cc
diff --git a/chrome/browser/ui/sync/profile_signin_confirmation_helper.cc b/chrome/browser/ui/sync/profile_signin_confirmation_helper.cc
index 4e9ce18ea9897fe4f313df7529d6e8ee59985325..9585fb97b11e7a046013018615e1ac8aa9b7a8e5 100644
--- a/chrome/browser/ui/sync/profile_signin_confirmation_helper.cc
+++ b/chrome/browser/ui/sync/profile_signin_confirmation_helper.cc
@@ -21,6 +21,7 @@
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/extensions/sync_helper.h"
 #include "components/bookmarks/browser/bookmark_model.h"
+#include "content/public/browser/browser_thread.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_set.h"
@@ -56,6 +57,7 @@ class HasTypedURLsTask : public history::HistoryDBTask {
 
  private:
   virtual ~HasTypedURLsTask() {}
+
   bool has_typed_urls_;
   base::Callback<void(bool)> cb_;
 };
@@ -69,19 +71,16 @@ bool HasBookmarks(Profile* profile) {
 }
 
 // Helper functions for Chrome profile signin.
-class ProfileSigninConfirmationHelper
-    : public base::RefCounted<ProfileSigninConfirmationHelper> {
+class ProfileSigninConfirmationHelper {
  public:
   ProfileSigninConfirmationHelper(
       Profile* profile,
       const base::Callback<void(bool)>& return_result);
   void CheckHasHistory(int max_entries);
   void CheckHasTypedURLs();
-  void set_pending_requests(int requests);
 
  private:
-  friend class base::RefCounted<ProfileSigninConfirmationHelper>;
-
+  // Deletes itself.
   ~ProfileSigninConfirmationHelper();
 
   void OnHistoryQueryResults(size_t max_entries,
@@ -97,9 +96,6 @@ class ProfileSigninConfirmationHelper
   // Keep track of how many async requests are pending.
   int pending_requests_;
 
-  // Indicates whether the result has already been returned to caller.
-  bool result_returned_;
-
   // Callback to pass the result back to the caller.
   const base::Callback<void(bool)> return_result_;
 
@@ -111,11 +107,11 @@ ProfileSigninConfirmationHelper::ProfileSigninConfirmationHelper(
     const base::Callback<void(bool)>& return_result)
     : profile_(profile),
       pending_requests_(0),
-      result_returned_(false),
       return_result_(return_result) {
 }
 
 ProfileSigninConfirmationHelper::~ProfileSigninConfirmationHelper() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 }
 
 void ProfileSigninConfirmationHelper::OnHistoryQueryResults(
@@ -134,6 +130,7 @@ void ProfileSigninConfirmationHelper::OnHistoryQueryResults(
 void ProfileSigninConfirmationHelper::CheckHasHistory(int max_entries) {
   HistoryService* service =
       HistoryServiceFactory::GetForProfileWithoutCreating(profile_);
+  pending_requests_++;
   if (!service) {
     ReturnResult(false);
     return;
@@ -144,7 +141,7 @@ void ProfileSigninConfirmationHelper::CheckHasHistory(int max_entries) {
       base::string16(),
       opts,
       base::Bind(&ProfileSigninConfirmationHelper::OnHistoryQueryResults,
-                 this,
+                 base::Unretained(this),
                  max_entries),
       &task_tracker_);
 }
@@ -152,27 +149,28 @@ void ProfileSigninConfirmationHelper::CheckHasHistory(int max_entries) {
 void ProfileSigninConfirmationHelper::CheckHasTypedURLs() {
   HistoryService* service =
       HistoryServiceFactory::GetForProfileWithoutCreating(profile_);
+  pending_requests_++;
   if (!service) {
     ReturnResult(false);
     return;
   }
   service->ScheduleDBTask(
       new HasTypedURLsTask(
-          base::Bind(&ProfileSigninConfirmationHelper::ReturnResult, this)),
+          base::Bind(&ProfileSigninConfirmationHelper::ReturnResult,
+                     base::Unretained(this))),
       &task_tracker_);
 }
 
-void ProfileSigninConfirmationHelper::set_pending_requests(int requests) {
-  pending_requests_ = requests;
-}
-
 void ProfileSigninConfirmationHelper::ReturnResult(bool result) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   // Pass |true| into the callback as soon as one of the tasks passes a
   // result of |true|, otherwise pass the last returned result.
-  if (!result_returned_ && (--pending_requests_ == 0 || result)) {
-    result_returned_ = true;
-    task_tracker_.TryCancelAll();
+  if (--pending_requests_ == 0 || result) {
     return_result_.Run(result);
+
+    // This leaks at shutdown if the HistoryService is destroyed, but
+    // the process is going to die anyway.
+    delete this;
   }
 }
 
@@ -220,6 +218,8 @@ bool HasSyncedExtensions(Profile* profile) {
 void CheckShouldPromptForNewProfile(
     Profile* profile,
     const base::Callback<void(bool)>& return_result) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
   if (HasBeenShutdown(profile) ||
       HasBookmarks(profile) ||
       HasSyncedExtensions(profile)) {
@@ -227,10 +227,8 @@ void CheckShouldPromptForNewProfile(
     return;
   }
   // Fire asynchronous queries for profile data.
-  scoped_refptr<ProfileSigninConfirmationHelper> helper =
+  ProfileSigninConfirmationHelper* helper =
       new ProfileSigninConfirmationHelper(profile, return_result);
-  const int requests = 2;
-  helper->set_pending_requests(requests);
   helper->CheckHasHistory(kHistoryEntriesBeforeNewProfilePrompt);
   helper->CheckHasTypedURLs();
 }