Revert of Remove WheelEvent.initWebKitWheelEvent()

Revert of Remove WheelEvent.initWebKitWheelEvent() (https://codereview.chromium.org/425633002/)

Reason for revert:
This change broke the following browser_tests:
NetInternalsTest.netInternalsTimelineViewDegenerate
NetInternalsTest.netInternalsTimelineViewNoEvents
NetInternalsTest.netInternalsTimelineViewZoomIn
NetInternalsTest.netInternalsTimelineViewZoomOut

http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/38303

Original issue's description:
> Remove WheelEvent.initWebKitWheelEvent()
> 
> Intent to Deprecate and Remove:
> https://groups.google.com/a/chromium.org/d/msg/blink-dev/h_GoezQ4MQ4/Q5abFkhA76sJ
> 
> BUG=398422
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179183

TBR=tkent@chromium.org,philipj@opera.com
NOTREECHECKS=true
NOTRY=true
BUG=398738
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179198

[alancutter (OOO until 2018), 2014-07-30 05:07:11]

Created Revert of Remove WheelEvent.initWebKitWheelEvent()

[alancutter (OOO until 2018), 2014-07-30 05:07:16]

The CQ bit was unchecked by alancutter@chromium.org

[alancutter (OOO until 2018), 2014-07-30 05:08:02]

The CQ bit was checked by alancutter@chromium.org

[commit-bot: I haz the power, 2014-07-30 05:08:53]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/alancutter@chromium.org/429803002/1

[commit-bot: I haz the power, 2014-07-30 05:09:29]

Change committed as 179198

[tkent, 2014-07-30 05:14:10]

lgtm