Fixed memory leak in Password Manager UI.

chrome/browser/ui/views/passwords/credentials_selection_view.cc

 // Copyright 2015 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 "chrome/browser/ui/views/passwords/credentials_selection_view.h"
 
 #include <stddef.h>
 
 #include "chrome/browser/ui/passwords/manage_passwords_bubble_model.h"
 #include "components/password_manager/core/browser/password_manager_metrics_util.h"
@@ skipping 37 matching lines @@
   column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL, 1,
                         views::GridLayout::FIXED, 0, 0);
   column_set->AddPaddingColumn(0, views::kItemLabelSpacing);
   column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL, 1,
                         views::GridLayout::FIXED, 0, 0);
   column_set->AddPaddingColumn(0, views::kItemLabelSpacing);
 
   // The username combobox and password label.
   layout->StartRowWithPadding(0, column_set_id, 0,
                               views::kRelatedControlVerticalSpacing);
-  combobox_ = GenerateUsernameCombobox(
+  GenerateUsernameCombobox(
       manage_passwords_bubble_model->pending_password().username_value);
-  layout->AddView(combobox_);
+  layout->AddView(combobox_.get());
   views::Label* label =
       GeneratePasswordLabel(manage_passwords_bubble_model->pending_password());
   layout->AddView(label);
 
   GetLayoutManager()->Layout(this);
 }
 
 CredentialsSelectionView::~CredentialsSelectionView() {
   ReportUserActionOnce(true, -1);
+  // |combobox_| has a pointer to |combobox_model_|, so |combobox_| should be
+  // deleted before deleting of |combobox_model_|. To ensure this, let's delete
+  // it now.
+  combobox_.reset();

[Mathieu, 2017/02/15 13:46:57]

you could also have combobox_model_ be above combobox_ in the member list. C++
destroys members in reverse order of their instantiation

[dvadym, 2017/02/15 13:57:13]

Yeah, sure. In other places it was done this way. But I like more explicit way,
probably just matter of preferences. 

 }
 
 const autofill::PasswordForm*
 CredentialsSelectionView::GetSelectedCredentials() {
   DCHECK_EQ(password_forms_->size(),
             static_cast<size_t>(combobox_->model()->GetItemCount()));
   ReportUserActionOnce(false, combobox_->selected_index());
   return &password_forms_->at(combobox_->selected_index());
 }
 
-views::Combobox* CredentialsSelectionView::GenerateUsernameCombobox(
+void CredentialsSelectionView::GenerateUsernameCombobox(
     const base::string16& best_matched_username) {
   std::vector<base::string16> usernames;
   size_t best_matched_username_index = password_forms_->size();
   size_t preferred_form_index = password_forms_->size();
   for (size_t index = 0; index < password_forms_->size(); ++index) {
     usernames.push_back(password_forms_->at(index).username_value);
     if (password_forms_->at(index).username_value == best_matched_username) {
       best_matched_username_index = index;
     }
     if (password_forms_->at(index).preferred) {
       preferred_form_index = index;
     }
   }
 
-  views::Combobox* combobox =
-      new views::Combobox(new ui::SimpleComboboxModel(usernames));
+  combobox_model_.reset(new ui::SimpleComboboxModel(usernames));
+  combobox_.reset(new views::Combobox(combobox_model_.get()));
 
   if (best_matched_username_index < password_forms_->size()) {
     is_default_best_match_ = true;
     default_index_ = best_matched_username_index;
-    combobox->SetSelectedIndex(best_matched_username_index);
+    combobox_->SetSelectedIndex(best_matched_username_index);
   } else if (preferred_form_index < password_forms_->size()) {
     is_default_preferred_ = true;
     default_index_ = preferred_form_index;
-    combobox->SetSelectedIndex(preferred_form_index);
+    combobox_->SetSelectedIndex(preferred_form_index);
   }
-  return combobox;
 }
 
 void CredentialsSelectionView::ReportUserActionOnce(bool was_update_rejected,
                                                     int selected_index) {
   if (action_reported_)
     return;
   password_manager::metrics_util::MultiAccountUpdateBubbleUserAction action;
   if (was_update_rejected) {
     if (is_default_best_match_) {
       action = password_manager::metrics_util::
@@ skipping 25 matching lines @@
           DEFAULT_ACCOUNT_PREFERRED_USER_CHANGED;
     } else {
       action =
           password_manager::metrics_util::DEFAULT_ACCOUNT_FIRST_USER_CHANGED;
     }
   }
 
   password_manager::metrics_util::LogMultiAccountUpdateBubbleUserAction(action);
   action_reported_ = true;
 }