Fix DCHECK, memory leak, and refactor PasswordStore to use CancelableRequest

chrome/browser/password_manager/password_form_manager.h

Index: chrome/browser/password_manager/password_form_manager.h
diff --git a/chrome/browser/password_manager/password_form_manager.h b/chrome/browser/password_manager/password_form_manager.h
index 698c3e2b0e297107b7362339d1d6448132a81803..e4eb98636db2666d08f86533732bf7749a800780 100644
--- a/chrome/browser/password_manager/password_form_manager.h
+++ b/chrome/browser/password_manager/password_form_manager.h
@@ -72,7 +72,8 @@ class PasswordFormManager : public PasswordStoreConsumer {
 
   // PasswordStoreConsumer implementation.
   virtual void OnPasswordStoreRequestDone(
-      int handle, const std::vector<webkit_glue::PasswordForm*>& result);
+      PasswordStore::Handle handle,
+      const std::vector<webkit_glue::PasswordForm*>& result);
 
   // A user opted to 'never remember' passwords for this form.
   // Blacklist it so that from now on when it is seen we ignore it.
@@ -136,10 +137,6 @@ class PasswordFormManager : public PasswordStoreConsumer {
   static const int kMaxNumActionsTaken = kManagerActionMax * kUserActionMax *
                                          kSubmitResultMax;
 
-  // Called by destructor to ensure if this object is deleted, no potential
-  // outstanding callbacks can call OnPasswordStoreRequestDone.
-  void CancelLoginsQuery();
-
   // Helper for OnPasswordStoreRequestDone to determine whether or not
   // the given result form is worth scoring.
   bool IgnoreResult(const webkit_glue::PasswordForm& form) const;
@@ -197,7 +194,7 @@ class PasswordFormManager : public PasswordStoreConsumer {
   const PasswordManager* const password_manager_;
 
   // Handle to any pending PasswordStore::GetLogins query.
-  int pending_login_query_;
+  PasswordStore::Handle pending_login_query_;
 
   // Convenience pointer to entry in best_matches_ that is marked
   // as preferred. This is only allowed to be null if there are no best matches