Revert of Preventing the default action on 'mousemove' listener shouldn't prevent selection

Revert of Preventing the default action on 'mousemove' listener shouldn't prevent selection (patchset #6 id:100001 of https://codereview.chromium.org/1013303003/)

Reason for revert:
Revert because there are applications (like Google maps - http://crbug.com/485892) which are relying on disabling text selection / drag and drop but are forced to avoid cancelling mousedown (due to http://crbug.com/269917).

Original issue's description:
> Preventing the default action on 'mousemove' listener shouldn't prevent selection
> 
> As per the spec, mousemove has no default action: 
> http://www.w3.org/TR/DOM-Level-3-Events/#event-type-mousemove.
> Hence preventing the default action on mousemove should not 
> prevent selection/drag from happening. Made changes to 
> allow drag operation irrespective of mousemove event 
> cancellation similar to behavior of other browsers.
> 
> BUG=346473
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=192855

TBR=leviw@chromium.org,ojan@chromium.org,rob.buis@samsung.com,ramya.v@samsung.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=346473
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195334

[Rick Byers, 2015-05-14 01:57:12]

Created Revert of Preventing the default action on 'mousemove' listener
shouldn't prevent selection

[commit-bot: I haz the power, 2015-05-14 01:57:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1145433002/1

[commit-bot: I haz the power, 2015-05-14 01:58:41]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=195334