Revert of Include event type name in tracing output for EventDispatcher (https://codereview.chromium.org/256873004/)

Reason for revert:
This appears to be causing crashes during touchpad scroll on Mac when about:tracing is active.

Original issue's description:
> Include event type name in tracing output for EventDispatcher
> 
> R=ojan
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=172670

TBR=ojan@chromium.org,esprehn@chromium.org,rafaelw@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=368397

Review URL: https://codereview.chromium.org/255283004

git-svn-id: svn://svn.chromium.org/blink/trunk@172886 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Re-Enable Repaint-After-Layout by default.

This CL reenables the new repaint-after-layout feature. This changes the way
that we do repainting in Blink and has the potential to cause under-painting.

If you see underpainting issues, please try with --disable-repaint-after-layout
and see if the issue persists.

Landing on behalf of dsinclair@.

TBR=jchaffraix,dsinclair
BUG=320139

Review URL: https://codereview.chromium.org/263463004

git-svn-id: svn://svn.chromium.org/blink/trunk@172887 bbb929c8-8fbe-4397-9dbb-9b2b20218538