Fix memory leak for extension uninstall dialog.

chrome/browser/ui/views/extensions/extension_uninstall_dialog_view.cc

 // Copyright (c) 2012 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 <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 26 matching lines @@
 class ExtensionUninstallDialogViews
     : public extensions::ExtensionUninstallDialog {
  public:
   ExtensionUninstallDialogViews(
       Profile* profile,
       gfx::NativeWindow parent,
       extensions::ExtensionUninstallDialog::Delegate* delegate);
   ~ExtensionUninstallDialogViews() override;
 
   // Called when the ExtensionUninstallDialogDelegate has been destroyed to make
-  // sure we invalidate pointers.
-  void DialogDelegateDestroyed() { view_ = NULL; }
+  // sure we invalidate pointers. This object will also be freed.
+  void DialogDelegateDestroyed();
 
   // Forwards the accept and cancels to the delegate.
   void DialogAccepted(bool handle_report_abuse);
   void DialogCanceled();
 
  private:
   void Show() override;
 
   ExtensionUninstallDialogDelegateView* view_;
 
@@ skipping 74 matching lines @@
   if (parent_ && parent_window_tracker_->WasNativeWindowClosed()) {
     OnDialogClosed(CLOSE_ACTION_CANCELED);
     return;
   }
 
   view_ = new ExtensionUninstallDialogDelegateView(
       this, triggering_extension() != nullptr, &icon());
   constrained_window::CreateBrowserModalDialogViews(view_, parent_)->Show();
 }
 
+void ExtensionUninstallDialogViews::DialogDelegateDestroyed() {
+  // Checks view_ to ensure OnDialogClosed() will not be called twice.
+  if (view_) {
+    view_ = NULL;

[Devlin, 2016/11/14 17:49:12]

nit: prefer nullptr in new code.

[lgcheng, 2016/11/14 19:10:33]

Done.

+    OnDialogClosed(CLOSE_ACTION_CANCELED);
+  }
+}
+
 void ExtensionUninstallDialogViews::DialogAccepted(bool report_abuse_checked) {
   // The widget gets destroyed when the dialog is accepted.
+  DCHECK(view_);
   view_->DialogDestroyed();
   view_ = nullptr;
   OnDialogClosed(report_abuse_checked ?
       CLOSE_ACTION_UNINSTALL_AND_REPORT_ABUSE : CLOSE_ACTION_UNINSTALL);
 }
 
 void ExtensionUninstallDialogViews::DialogCanceled() {
   // The widget gets destroyed when the dialog is canceled.
+  DCHECK(view_);
   view_->DialogDestroyed();
   view_ = nullptr;
   OnDialogClosed(CLOSE_ACTION_CANCELED);
 }
 
 ExtensionUninstallDialogDelegateView::ExtensionUninstallDialogDelegateView(
     ExtensionUninstallDialogViews* dialog_view,
     bool triggered_by_extension,
     const gfx::ImageSkia* image)
     : dialog_(dialog_view),
@@ skipping 106 matching lines @@
 
 }  // namespace
 
 // static
 extensions::ExtensionUninstallDialog*
 extensions::ExtensionUninstallDialog::Create(Profile* profile,
                                              gfx::NativeWindow parent,
                                              Delegate* delegate) {
   return new ExtensionUninstallDialogViews(profile, parent, delegate);
 }