Moving WebInputEvent into public/platform lets us refer to it directly in core, which will let us remove the PlatformFooEvent classes.
The final pipeline will be:
1) mojo::InputEvent (IPC type, device pixels)
2) blink::WebInputEvent (platform abstraction, logical pixels)
3) blink::Event (DOM type, logical pixels)
If mojo::InputEvent used logical pixels, it would probably be easier to just
use mojo::InputEvent as the platform abstraction, but instead we use the
mojo-to-blink conversion to translate between device and logical pixels, like
we do everywhere else in Sky.
R=eseidel@google.com, eseidel@chromium.org
Review URL: https://codereview.chromium.org/860593003
