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

chrome/browser/password_manager/password_form_manager.cc

Index: chrome/browser/password_manager/password_form_manager.cc
diff --git a/chrome/browser/password_manager/password_form_manager.cc b/chrome/browser/password_manager/password_form_manager.cc
index 11efdd224d83bf079c74371dba024b4ef0f44b80..312e820d840924ebd6e48d66db15ece639f9f3a4 100644
--- a/chrome/browser/password_manager/password_form_manager.cc
+++ b/chrome/browser/password_manager/password_form_manager.cc
@@ -25,7 +25,7 @@ PasswordFormManager::PasswordFormManager(Profile* profile,
       observed_form_(observed_form),
       is_new_login_(true),
       password_manager_(password_manager),
-      pending_login_query_(0),
+      pending_login_query_(PasswordStore::kInvalidHandle),
       preferred_match_(NULL),
       state_(PRE_MATCHING_PHASE),
       profile_(profile),
@@ -39,7 +39,6 @@ PasswordFormManager::PasswordFormManager(Profile* profile,
 }
 
 PasswordFormManager::~PasswordFormManager() {
-  CancelLoginsQuery();
   UMA_HISTOGRAM_ENUMERATION("PasswordManager.ActionsTaken",
                             GetActionsTaken(),
                             kMaxNumActionsTaken);
@@ -197,7 +196,7 @@ void PasswordFormManager::Save() {
 
 void PasswordFormManager::FetchMatchingLoginsFromPasswordStore() {
   DCHECK_EQ(state_, PRE_MATCHING_PHASE);
-  DCHECK(!pending_login_query_);
+  DCHECK(!PasswordStore::handle_is_valid(pending_login_query_));
   state_ = MATCHING_PHASE;
   PasswordStore* password_store =
       profile_->GetPasswordStore(Profile::EXPLICIT_ACCESS);
@@ -306,7 +305,8 @@ void PasswordFormManager::OnRequestDone(int handle,
 }
 
 void PasswordFormManager::OnPasswordStoreRequestDone(
-    int handle, const std::vector<PasswordForm*>& result) {
+    PasswordStore::Handle handle,
+    const std::vector<PasswordForm*>& result) {
   DCHECK_EQ(state_, MATCHING_PHASE);
   DCHECK_EQ(pending_login_query_, handle);
 
@@ -316,6 +316,7 @@ void PasswordFormManager::OnPasswordStoreRequestDone(
   }
 
   OnRequestDone(handle, result);
+  pending_login_query_ = PasswordStore::kInvalidHandle;
 }
 
 bool PasswordFormManager::IgnoreResult(const PasswordForm& form) const {
@@ -420,16 +421,6 @@ void PasswordFormManager::UpdateLogin() {
   }
 }
 
-void PasswordFormManager::CancelLoginsQuery() {
-  PasswordStore* password_store =
-      profile_->GetPasswordStore(Profile::EXPLICIT_ACCESS);
-  if (!password_store) {
-    // Can be NULL in unit tests.
-    return;
-  }
-  password_store->CancelLoginsQuery(pending_login_query_);
-}
-
 int PasswordFormManager::ScoreResult(const PasswordForm& candidate) const {
   DCHECK_EQ(state_, MATCHING_PHASE);
   // For scoring of candidate login data: