Removes IsInterestedInKeyEvent() method in IMEEngineHandlerInterface.

This makes the non-mojo-imf and mojo-imf have the consistent logic to handle key events.

Bug: 937167
Change-Id: I90a9a8ce8a776a4144203062b56297d2fcb572f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574981
Reviewed-by: Lan Wei <azurewei@chromium.org>
Commit-Queue: Shu Chen <shuchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652462}
11 files changed