GitLab

When |ContextDestroyed| was called in the InputMethodController,
the active EditContext stored in the InputMethodController wasn't
getting destroyed so explicitly setting it to null in |ContextDestroyed|.

Bug: 1024161
Change-Id: I49489f90b13aa105c2ae6dffdaae19546e31f290
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1925891Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Anupam Snigdha <snianu@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#717230}