[Refactor] Consolidate the logic for whether a widget can be activated.

ash/wm/panels/panel_layout_manager.cc

Index: ash/wm/panels/panel_layout_manager.cc
diff --git a/ash/wm/panels/panel_layout_manager.cc b/ash/wm/panels/panel_layout_manager.cc
index 5a8d2e935e3a31faf2d2e17c87893d454bdfe056..234adb9c36a89ba571c0283074b0e495b0565712 100644
--- a/ash/wm/panels/panel_layout_manager.cc
+++ b/ash/wm/panels/panel_layout_manager.cc
@@ -229,7 +229,6 @@ class PanelCalloutWidget : public views::Widget {
     views::Widget::InitParams params;
     params.type = views::Widget::InitParams::TYPE_POPUP;
     params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
-    params.can_activate = false;
     params.keep_on_top = true;
     params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
     params.parent = parent;
@@ -237,7 +236,6 @@ class PanelCalloutWidget : public views::Widget {
     params.bounds.set_width(kArrowWidth);
     params.bounds.set_height(kArrowHeight);
     params.accept_events = false;
-    // Why do we need this and can_activate = false?
     set_focus_on_creation(false);
     Init(params);
     DCHECK_EQ(GetNativeView()->GetRootWindow(), parent->GetRootWindow());