Refactor event handler classes to make it easier to add new event type listeners.
A new event type, activedescendantchanged, was added.
Moving forward, it will be simpler to separate handlers (which contain groups of events), into separate classes. BaseAutomationHandler will provide basic utilities that are useful when daeling with a group of extension-styled event listeners (e.g. adding/removing, binding, etc).
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:closure_compilation
Review-Url: https://codereview.chromium.org/1942683005
Cr-Commit-Position: refs/heads/master@{#391395}
10 files changed
