Enables hot-tracking for overflow extension buttons in the app menu

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 1cd057e8dcfc1e33813236383bba75570df59295..5f7389a6bf07b4a1efa36d004e51ae57bc824f8a 100644
--- a/ui/views/controls/menu/menu_controller.cc
+++ b/ui/views/controls/menu/menu_controller.cc
@@ -114,6 +114,21 @@ static CustomButton* GetFirstHotTrackedView(View* view) {
   return NULL;
 }
 
+CustomButton* OtherHotTrackedButton(View* view, CustomButton* button_hot) {
+  if (!view)
+    return nullptr;
+  CustomButton* button = CustomButton::AsCustomButton(view);
+  if (button && button != button_hot && button->IsHotTracked())
+    return button;
+
+  for (int i = 0; i < view->child_count(); ++i) {
+    button = OtherHotTrackedButton(view->child_at(i), button_hot);
+    if (button)
+      return button;
+  }
+  return nullptr;
+}
+
 // Recurses through the child views of |view| returning the first view starting
 // at |start| that is focusable. A value of -1 for |start| indicates to start at
 // the first view (if |forward| is false, iterating starts at the last view). If
@@ -939,7 +954,13 @@ void MenuController::SetSelection(MenuItemView* menu_item,
   if (pending_item_changed && pending_state_.item) {
     CustomButton* button = GetFirstHotTrackedView(pending_state_.item);
     if (button)
-      button->SetHotTracked(false);
+      SetHotTrackedButton(button, false);
+  }
+  CustomButton* new_hot_button = OtherHotTrackedButton(menu_item, hot_button_);
+  if (new_hot_button) {
+    if (hot_button_)
+      SetHotTrackedButton(hot_button_, false);
+    SetHotTrackedButton(new_hot_button, true);
   }
 
   // Notify the old path it isn't selected.
@@ -1191,6 +1212,7 @@ 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()),
@@ -1226,8 +1248,7 @@ 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(hot_view, true);
   return true;
 }
 
@@ -1989,8 +2010,7 @@ void MenuController::IncrementSelection(
     // select the first menu item that is visible and enabled.
     if (item->GetSubmenu()->GetMenuItemCount()) {
       MenuItemView* to_select = FindInitialSelectableMenuItem(item, direction);
-      if (to_select)
-        SetSelection(to_select, SELECTION_DEFAULT);
+      SetInitialHotTrackedView(to_select, direction);
       return;
     }
   }
@@ -1998,12 +2018,12 @@ void MenuController::IncrementSelection(
   if (item->has_children()) {
     CustomButton* button = GetFirstHotTrackedView(item);
     if (button) {
-      button->SetHotTracked(false);
+      SetHotTrackedButton(button, false);
       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, true);
         return;
       }
     } else {
@@ -2011,7 +2031,7 @@ 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, true);
         return;
       }
     }
@@ -2025,14 +2045,7 @@ void MenuController::IncrementSelection(
         if (parent->GetSubmenu()->GetMenuItemAt(i) == item) {
           MenuItemView* to_select =
               FindNextSelectableMenuItem(parent, i, direction);
-          if (!to_select)
-            break;
-          SetSelection(to_select, SELECTION_DEFAULT);
-          View* to_make_hot = GetInitialFocusableView(
-              to_select, direction == INCREMENT_SELECTION_DOWN);
-          CustomButton* button_hot = CustomButton::AsCustomButton(to_make_hot);
-          if (button_hot)
-            button_hot->SetHotTracked(true);
+          SetInitialHotTrackedView(to_select, direction);
           break;
         }
       }
@@ -2597,4 +2610,30 @@ void MenuController::HandleMouseLocation(SubmenuView* source,
   }
 }
 
+void MenuController::SetHotTrackedButton(CustomButton* hot_button,
+                                         bool is_hot_tracked) {
+  DCHECK(hot_button);
+  hot_button->SetHotTracked(is_hot_tracked);
+  if (is_hot_tracked)
+    hot_button_ = hot_button;
+  else if (hot_button_ == hot_button)
+    hot_button_ = nullptr;
+  else
+    NOTREACHED();

[Peter Kasting, 2016/02/06 02:51:12]

Nit: Simpler:

  DCHECK(is_hot_tracked || (hot_button_ == hot_button));
  hot_button_ = is_hot_tracked ? hot_button : nullptr;

[varkha, 2016/02/16 19:59:44]

Done.

+}
+
+void MenuController::SetInitialHotTrackedView(
+    MenuItemView* item,
+    SelectionIncrementDirectionType direction) {
+  if (!item)
+    return;
+  SetSelection(item, SELECTION_DEFAULT);
+  View* to_make_hot =

[Peter Kasting, 2016/02/06 02:51:13]

Nit: |hot_view| is shorter and, to me, less awkward but just as clear; it's also
parallel with my next suggestion

[varkha, 2016/02/16 19:59:44]

Done.

+      GetInitialFocusableView(item, direction == INCREMENT_SELECTION_DOWN);
+  CustomButton* button_hot = CustomButton::AsCustomButton(to_make_hot);

[Peter Kasting, 2016/02/06 02:51:12]

Nit: Use |hot_button| for consistency with previous function

[varkha, 2016/02/16 19:59:44]

Done.

+  if (button_hot)
+    SetHotTrackedButton(button_hot, true);
+  return;
+}
+
 }  // namespace views