[InputEvent] Replace |EditAction| with |InputType|

|EditAction| is used to describe editing operations in
Blink internal only, however with the introduction of
|InputEvent| we got a new type |InputType| which does the
same thing and SPECed.

Since having both is redundant, this CL removes
|EditAction| and finalized the list of possible
|InputType|.

This CL shouldn't have too much web-exposed effect (except
some trivial command mapping).

BUG=627740
Intent to Implement:
https://groups.google.com/a/chromium.org/forum/#!searchin/blink-dev/InputEvent/blink-dev/RrnitB0OElc/rirueVekCwAJ

Review-Url: https://codereview.chromium.org/2151353002
Cr-Commit-Position: refs/heads/master@{#407073}
36 files changed