Since the Device*EventPump and GamepadSharedMemoryReader classes have been decoupled from PlatformEventObserver, there is no more need for platform_event_observers_ member variable and logic in RendererBlinkPlatformImpl. blink::WebPlatformEventType is no longer used either. This ticket covers removing unused code.
Comment 1 by kojii@chromium.org
, Jun 25 2018