Issue 846889  has been merged into this issue.

Im not to familiar with tab dragging but it looks like its still in maximized state, but transformed?

If so we can change [1] and add a ShouldIgnoreShowState to our delegate or something and that might work.

[1] https://cs.chromium.org/chromium/src/ui/wm/core/shadow_controller.cc?rcl=54738d34a08ba7be6a0bef44b2e53150396e22f9&l=260

It may be in maximized state or fullscreen state, but either transfromed (if dragging window) or resized (if dragging tabs). But I think your proposal should work. Thanks for the suggestion!

Ben, besides enable the active window shadow for a pulled out tab window, do we want the active window shadow for the following cases:
1) If a browser window only has one tab, and drag this tab around (the browser window might not be the current active window)
2) If drag on the non-tab caption area to drag the window (same as 1), the browser window might not be the current active window)

Good question. Does the dragged window or tab become the active window on release in these scenarios?

Currently not necessarily. But we may be able to set it as the active window for these 2 scenarios (If the window was not snapped in splitview or merged into overview)

Yeah, I've been thinking about it. I think dragging a window or tab should always give it focus / make it the active window. Whether or not it goes to overview, it becomes the last window the user interacted with.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b7ee049e2130a36eba7734b648b07f1a60bbca2c

commit b7ee049e2130a36eba7734b648b07f1a60bbca2c
Author: Xiaoqian Dai <xdai@chromium.org>
Date: Tue Aug 21 22:09:36 2018

Dragged window should have active window shadow during dragging.

Bug:  874261 
Change-Id: I5973ae1a7afd1a0ffd6f2dd61df679cc566e998a
Reviewed-on: https://chromium-review.googlesource.com/1180253
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Mitsuru Oshima (Slow) <oshima@chromium.org>
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584906}
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ash/BUILD.gn
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ash/wm/splitview/split_view_controller_unittest.cc
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ash/wm/tablet_mode/tablet_mode_window_drag_delegate.cc
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ash/wm/tablet_mode/tablet_mode_window_drag_delegate.h
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ash/wm/wm_shadow_controller_delegate.cc
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ui/wm/core/shadow_controller.cc
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ui/wm/core/shadow_types.cc
[modify] https://crrev.com/b7ee049e2130a36eba7734b648b07f1a60bbca2c/ui/wm/core/shadow_types.h