Revert 236254 "Replace old with new synthetic gesture framework."

> Replace old with new synthetic gesture framework.
> 
> - Remove current implementation of synthetic gestures.
> - Rename temporarily named classes and files of new synthetic gesture framework
>   (e.g. SyntheticGestureNew -> SyntheticGesture).
> - Link up new implementation in browser and renderer.
> - Hook up synthetic gesture controller to input flushing in RWHI.
> - Update JavaScript front-end and Telemetry.
> 
> BUG=297980
> 
> Review URL: https://codereview.chromium.org/62443007

TBR=dominikg@chromium.org

Review URL: https://codereview.chromium.org/79143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236264 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236264