Fix AdjustBoundsToEnsureWindowVisibility to work with non primary display bounds

ash/wm/dock/docked_window_layout_manager.cc

Index: ash/wm/dock/docked_window_layout_manager.cc
diff --git a/ash/wm/dock/docked_window_layout_manager.cc b/ash/wm/dock/docked_window_layout_manager.cc
index 0a648a025f748303a10c7c27d0f6a78dfeedee28..5d16a24ca5f2e8a3e94e46b84e60a88a22aee745 100644
--- a/ash/wm/dock/docked_window_layout_manager.cc
+++ b/ash/wm/dock/docked_window_layout_manager.cc
@@ -593,6 +593,9 @@ void DockedWindowLayoutManager::OnWindowAddedToLayout(aura::Window* child) {
   if (child == dragged_window_)
     return;
   // If this is the first window getting docked - update alignment.
+  // TODO(oshima|varkha): A window can be added without proper bounds when
+  // window is moved to another display via API or due to display configuration
+  // change, so the the alignment may not be valid.
   if (alignment_ == DOCKED_ALIGNMENT_NONE) {
     alignment_ = GetAlignmentOfWindow(child);
     DCHECK(alignment_ != DOCKED_ALIGNMENT_NONE);