[Views] Set Correct Menu Orientation

Toolkit-views menus positioned with POSITION_BEST_FIT are be
positioned to the side of the anchor when the menu height is greater
than ~50% of the screen. Currently in this situation, the "actual"
position of the menu is incorrectly recorded as POSITION_BELOW_BOUNDS.
If a menu delegate invokes MenuChildrenChanged() and recalculates the
menu bounds, this can cause the menu to reposition itself under
the anchor rather than remaining to the side.

To fix, record the "actual" position as POSITION_BEST_FIT in this
situation.

Bug: 840919
Change-Id: I4102e014c058b2f89d5bc38b7b4371c010367119
Reviewed-on: https://chromium-review.googlesource.com/1087516
Commit-Queue: Tessa Nijssen <tnijssen@google.com>
Reviewed-by: Sarah Chan <spqchan@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565352}

ui/views/controls/menu/menu_controller.cc

@@ -2046,7 +2046,7 @@ gfx::Rect MenuController::CalculateMenuBounds(MenuItemView* item,
       } else if (item->actual_menu_position() ==
                  MenuItemView::POSITION_BEST_FIT) {
         MenuItemView::MenuPosition orientation =
-            MenuItemView::POSITION_BELOW_BOUNDS;
+            MenuItemView::POSITION_BEST_FIT;
         if (state_.monitor_bounds.height() < pref.height()) {
           // Handle very tall menus.
           pref.set_height(state_.monitor_bounds.height());
@@ -2061,7 +2061,7 @@ gfx::Rect MenuController::CalculateMenuBounds(MenuItemView* item,
           // best fit and to avoid showing scroll elements.
           y = state_.monitor_bounds.bottom() - pref.height();
         }
-        if (orientation == MenuItemView::POSITION_BELOW_BOUNDS) {
+        if (orientation == MenuItemView::POSITION_BEST_FIT) {
           // The menu should never overlap the owning button. So move it.
           // We use the anchor view style to determine the preferred position
           // relative to the owning button.