Revert "DragController: Clear DragState in DragEnd"

This reverts commit 5a47d400c29df3951d856e868a2981faff15d124.

Reason for revert: Maybe introduced breakage. See bugs.


Original change's description:
> DragController: Clear DragState in DragEnd
> 
> DragState is a ScriptWrappable which can keep alive JavaScript upon
> unified heap garbage collection resulting in a leak of the last Window
> that used a drag event. Clear the state when the drag ended.
> 
> Bug: 843903, 928781
> Change-Id: Id86a1a917fe772f56fb679e1d73ef3453785ce6d
> Reviewed-on: https://chromium-review.googlesource.com/c/1456073
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#629582}

TBR=haraken@chromium.org,mlippautz@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 843903, 928781, 930044, 930079
Change-Id: I64722d3fb1757b805440e9840613601634c5d370
Reviewed-on: https://chromium-review.googlesource.com/c/1461019
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630333}
1 file changed