GitLab

Changed DragDropController to:
- Cancel drop if not allowed by policy rules.
- Show CursorType::NoDrop while dragging if
the policy rules disallow the data from being
dropped.

Bug: 1139886
Change-Id: I8a12f1f4af2fa0f21d4d562d393d9f64cec39f72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2595382Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Aya Elsayed <ayaelattar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842939}