Merge Prevent nested Menu Cancelling

ui/views/controls/menu/menu_controller.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 "ui/views/controls/menu/menu_controller.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 487 matching lines @@
 
 void MenuController::Cancel(ExitType type) {
   // If the menu has already been destroyed, no further cancellation is
   // needed.  We especially don't want to set the |exit_type_| to a lesser
   // value.
   if (exit_type_ == EXIT_DESTROYED || exit_type_ == type)
     return;
 
   if (!showing_) {
     // This occurs if we're in the process of notifying the delegate for a drop
-    // and the delegate cancels us.
+    // and the delegate cancels us. Or if the releasing of ViewsDelegate causes
+    // an immediate shutdown.
     return;
   }
 
   MenuItemView* selected = state_.item;
   SetExitType(type);
 
   SendMouseCaptureLostToActiveView();
 
   // Hide windows immediately.
   SetSelection(NULL, SELECTION_UPDATE_IMMEDIATELY | SELECTION_EXIT);
 
   if (!blocking_run_) {
     // If we didn't block the caller we need to notify the menu, which
     // triggers deleting us.
     DCHECK(selected);
     showing_ = false;
     delegate_->OnMenuClosed(internal::MenuControllerDelegate::NOTIFY_DELEGATE,
                             selected->GetRootMenuItem(), accept_event_flags_);
     // WARNING: the call to MenuClosed deletes us.
     return;
   }
 
+  // If |type| is EXIT_ALL we update the state of the menu to not showing. For
+  // dragging this ensures that the correct visual state is reported until the
+  // drag operation completes. For non-dragging cases it is possible that the
+  // release of ViewsDelegate leads immediately to shutdown, which can trigger
+  // nested calls to Cancel. We want to reject these to prevent attempting a
+  // nested tear down of this and |delegate_|.
+  if (type == EXIT_ALL)
+    showing_ = false;
+
   // On Windows and Linux the destruction of this menu's Widget leads to the
   // teardown of the platform specific drag-and-drop Widget. Do not shutdown
   // while dragging, leave the Widget hidden until drag-and-drop has completed,
   // at which point all menus will be destroyed.
-  //
-  // If |type| is EXIT_ALL we update the state of the menu to not showing. So
-  // that during the completion of a drag we are not incorrectly reporting the
-  // visual state.
   if (!drag_in_progress_)
     ExitAsyncRun();
-  else if (type == EXIT_ALL)
-    showing_ = false;
 }
 
 void MenuController::AddNestedDelegate(
     internal::MenuControllerDelegate* delegate) {
   delegate_stack_.push_back(std::make_pair(delegate, async_run_));
   delegate_ = delegate;
 }
 
 void MenuController::SetAsyncRun(bool is_async) {
   delegate_stack_.back().second = is_async;
@@ skipping 2193 matching lines @@
   if (hot_button_)
     hot_button_->SetHotTracked(false);
   hot_button_ = hot_button;
   if (hot_button) {
     hot_button->SetHotTracked(true);
     hot_button->NotifyAccessibilityEvent(ui::AX_EVENT_SELECTION, true);
   }
 }
 
 }  // namespace views