The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ba1fdb52586c4c5eaeb182444552bc6f3d6b4711

commit ba1fdb52586c4c5eaeb182444552bc6f3d6b4711
Author: sky <sky@chromium.org>
Date: Wed Jul 27 19:55:16 2016

Makes DockedWindowLayoutManager::UpdateDockBounds() handle null shelf_

This is needed for mash as we asynchronously set the shelf, which is not expected. The async creation is temporary while we support sysui. Once sysui goes away this code shouldn't be needed.

BUG= 632099 
TEST=none
R=jamescook@chromium.org

Review-Url: https://codereview.chromium.org/2184223002
Cr-Commit-Position: refs/heads/master@{#408219}

[modify] https://crrev.com/ba1fdb52586c4c5eaeb182444552bc6f3d6b4711/ash/common/wm/dock/docked_window_layout_manager.cc

James and Mike, I believe that mus and classic ash create the shelf at the same time now. Is that right?

The timing of shelf creation is very similar, yes.

Similar, or the same? I'm specifically wondering if I can remove the conditional that I added for this. https://codereview.chromium.org/2184223002/diff/40001/ash/common/wm/dock/docked_window_layout_manager.cc

I just checked the code and they are the same. CreateShelfView() is called in WmShell::SessionStateChanged() when the user session becomes active. So I think it's probably OK to remove the null check. Either it will fail both in mash and in classic ash, or it will succeed in both.

The right fix here is to make DockedWindowLayoutManager take the WmShelf as a constructor parameter. WmShelf exists for the lifetime of the RootWindowController so there's no need to wait for the shelf *view* to be created.

Note that code for docking is probably going to be removed: https://codereview.chromium.org/2700523004/ (and issue 668355)

As docked windows are going away I'm going to close this out.