Fixes alternating keyboard and mouse hot-tracking in menus

ui/views/controls/menu/menu_controller.cc

Index: ui/views/controls/menu/menu_controller.cc
diff --git a/ui/views/controls/menu/menu_controller.cc b/ui/views/controls/menu/menu_controller.cc
index b271d959e78cb62b8d419e4999d4260f16395afb..0ca7547043cb3b71b8f9319d8ff264a986be41fc 100644
--- a/ui/views/controls/menu/menu_controller.cc
+++ b/ui/views/controls/menu/menu_controller.cc
@@ -715,11 +715,21 @@ void MenuController::OnMouseMoved(SubmenuView* source,
   }
 
   MenuHostRootView* root_view = GetRootView(source, event.location());
-  if (root_view)
+  if (root_view) {
     root_view->ProcessMouseMoved(event);
-  // TODO(varkha): It is possible that another child CustomButton has become
-  // hot-tracked as a result of this event. We need to track it for accurate
-  // hot-tracking when both mouse and keyboard are used to navigate the menu.
+
+    // Update hot-tracked button when a button state is changed with a mouse
+    // event. It is necessary to track it for accurate hot-tracking when both
+    // mouse and keyboard are used to navigate the menu.
+    ui::MouseEvent event_for_root(event);
+    ConvertLocatedEventForRootView(source, root_view, &event_for_root);
+    View* view =
+        root_view->GetEventHandlerForPoint(event_for_root.location());
+    CustomButton* button = CustomButton::AsCustomButton(view);
+    if (button && button->IsHotTracked())
+      SetHotTrackedButton(button);
+  }
+
   HandleMouseLocation(source, event.location());
 }
 
@@ -803,10 +813,15 @@ View* MenuController::GetTooltipHandlerForPoint(SubmenuView* source,
 void MenuController::ViewHierarchyChanged(
     SubmenuView* source,
     const View::ViewHierarchyChangedDetails& details) {
-  // If the current mouse handler is removed, remove it as the handler.
-  if (!details.is_add && details.child == current_mouse_event_target_) {
-    current_mouse_event_target_ = nullptr;
-    current_mouse_pressed_state_ = 0;
+  if (!details.is_add) {
+    // If the current mouse handler is removed, remove it as the handler.
+    if (details.child == current_mouse_event_target_) {
+      current_mouse_event_target_ = nullptr;
+      current_mouse_pressed_state_ = 0;
+    }
+    // Update |hot_button_| if it gets deleted while a menu is up.

[sky, 2016/02/29 16:33:32]

deleted->removed

[varkha, 2016/02/29 19:09:44]

Done.

+    if (details.child == hot_button_)
+      hot_button_ = nullptr;
   }
 }
 
@@ -1036,8 +1051,10 @@ void MenuController::SetSelection(MenuItemView* menu_item,
   bool pending_item_changed = pending_state_.item != menu_item;
   if (pending_item_changed && pending_state_.item) {
     CustomButton* button = GetFirstHotTrackedView(pending_state_.item);

[sky, 2016/02/29 16:33:32]

It doesn't seem necessary to call this anymore. Can't you just
SetHotTrackedButton(nullptr)?

[varkha, 2016/02/29 19:09:44]

Here, yes. Done.

-    if (button)
-      button->SetHotTracked(false);
+    if (button) {
+      DCHECK_EQ(hot_button_, button);
+      SetHotTrackedButton(nullptr);
+    }
   }
 
   // Notify the old path it isn't selected.
@@ -1289,6 +1306,7 @@ MenuController::MenuController(bool blocking,
       last_drop_operation_(MenuDelegate::DROP_UNKNOWN),
       showing_submenu_(false),
       active_mouse_view_id_(ViewStorage::GetInstance()->CreateStorageID()),
+      hot_button_(nullptr),
       delegate_(delegate),
       message_loop_depth_(0),
       closing_event_time_(base::TimeDelta()),
@@ -1325,7 +1343,7 @@ bool MenuController::SendAcceleratorToHotTrackedView() {
   ui::Accelerator accelerator(ui::VKEY_RETURN, ui::EF_NONE);
   hot_view->AcceleratorPressed(accelerator);
   CustomButton* button = static_cast<CustomButton*>(hot_view);
-  button->SetHotTracked(true);
+  SetHotTrackedButton(button);
   return true;
 }
 
@@ -2095,12 +2113,13 @@ void MenuController::IncrementSelection(
   if (item->has_children()) {
     CustomButton* button = GetFirstHotTrackedView(item);
     if (button) {
-      button->SetHotTracked(false);
+      DCHECK_EQ(hot_button_, button);
+      SetHotTrackedButton(nullptr);
       View* to_make_hot = GetNextFocusableView(
           item, button, direction == INCREMENT_SELECTION_DOWN);
       CustomButton* button_hot = CustomButton::AsCustomButton(to_make_hot);
       if (button_hot) {
-        button_hot->SetHotTracked(true);
+        SetHotTrackedButton(button_hot);
         return;
       }
     } else {
@@ -2108,7 +2127,7 @@ void MenuController::IncrementSelection(
           GetInitialFocusableView(item, direction == INCREMENT_SELECTION_DOWN);
       CustomButton* button_hot = CustomButton::AsCustomButton(to_make_hot);
       if (button_hot) {
-        button_hot->SetHotTracked(true);
+        SetHotTrackedButton(button_hot);
         return;
       }
     }
@@ -2612,7 +2631,15 @@ void MenuController::SetInitialHotTrackedView(
   SetSelection(item, SELECTION_DEFAULT);
   View* hot_view =
       GetInitialFocusableView(item, direction == INCREMENT_SELECTION_DOWN);
-  CustomButton* hot_button = CustomButton::AsCustomButton(hot_view);
+  SetHotTrackedButton(CustomButton::AsCustomButton(hot_view));
+}
+
+void MenuController::SetHotTrackedButton(CustomButton* hot_button) {
+  if (hot_button == hot_button_)
+    return;
+  if (hot_button_)
+    hot_button_->SetHotTracked(false);
+  hot_button_ = hot_button;
   if (hot_button)
     hot_button->SetHotTracked(true);
 }