Remove unused UseCounter features

Remove unused UseCounter features

These are the reviews in which the enum values became unused:

SVGInstanceRoot:
https://codereview.chromium.org/272523002

PromiseConstructor/PromiseCast/PromiseReject/PromiseResolve:
https://codereview.chromium.org/293933002

TextAutosizingLayout:
https://codereview.chromium.org/346603005

PrefixedElementRequestPointerLock/PrefixedDocumentExitPointerLock/PrefixedDocumentPointerLockElement:
https://codereview.chromium.org/437443005

PrefixedConvertPointFromPageToNode/PrefixedConvertPointFromNodeToPage:
https://codereview.chromium.org/428533003

MixedContentTextTrack:
https://codereview.chromium.org/348853009

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179627

[philipj_slow, 2014-08-06 13:13:53]

PTAL

[Mike West, 2014-08-06 13:24:56]

lgtm

Assuming it compiles, LGTM! Thanks for this cleanup.

[commit-bot: I haz the power, 2014-08-06 13:25:27]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/philipj@opera.com/442323002/1

[commit-bot: I haz the power, 2014-08-06 15:54:41]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_compile_dbg/bu...)

[commit-bot: I haz the power, 2014-08-06 16:19:58]

Change committed as 179627