Reland "Remove WheelEvent.initWebKitWheelEvent()"

Intent to Deprecate and Remove:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/h_GoezQ4MQ4/Q5abFkhA76sJ

The failing test in Chromium has been fixed.

BUG=398422, 398738

Review URL: https://codereview.chromium.org/426123004

git-svn-id: svn://svn.chromium.org/blink/trunk@179230 bbb929c8-8fbe-4397-9dbb-9b2b20218538
bindings: Workaround of missing EBCO of VC++.

VC++ doesn't support Empty Base Class Optimization.  Adds a workaround to avoid the bloat of instance size of CSSValue.  For details see the comment in CSSValue.h.

Review URL: https://codereview.chromium.org/423383003

git-svn-id: svn://svn.chromium.org/blink/trunk@179231 bbb929c8-8fbe-4397-9dbb-9b2b20218538