Revert of Implement suspend() and resume() for OfflineAudioContext

Revert of Implement suspend() and resume() for OfflineAudioContext (patchset #25 id:910001 of https://codereview.chromium.org/1140723003/)

Reason for revert:
Leak detected. (numberOfLiveActiveDOMObjects is non-zero)

Original issue's description:
> Adds suspend() and resume() feature in OfflineAudioContext to support the
> synchronous graph manipulation with the render block precision (k-rate) in the
> non-realtime audio rendering.
> 
> The benefit of being able to suspend/resume the context with the render block
> precision is:
> 
> 1) The audio graph can be modified in a time-accurate way, independent of the
>    hardware. Without this, setTimeout, completion events, or state change events
>    are needed to manipulate the graph, and the results depend on when the events
>    are fired and on how fast the hardware is.
> 
> 2) Makes an OfflineAudioContext more symmetrical to the AudioContext, which
>    already supports suspend/resume. (There are minor difference required by the
>    difference between offline and online contexts.)
> 
> This feature also can be used in Blink layout tests to verify the behavior of
> audio rendering. With this feature in the implementation, several flaky web
> audio layout tests can be fixed.
> 
> # Editor's draft spec PR:
> http://webaudio.github.io/web-audio-api/#the-offlineaudiocontext-interface
> 
> # Web Audio API issue tracker entry:
> https://github.com/WebAudio/web-audio-api/issues/302#issuecomment-106101885
> 
> 
> BUG=497933
> TEST=
> webaudio/offlineaudiocontext-suspend-resume-basic.html
> webaudio/offlineaudiocontext-suspend-resume-eventhandler.html
> webaudio/offlineaudiocontext-suspend-resume-graph-manipulation.html
> webaudio/offlineaudiocontext-suspend-resume-promise.html
> webaudio/offlineaudiocontext-suspend-resume-sequence.html
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=199129

TBR=haraken@chromium.org,oilpan-reviews@chromium.org,rtoy@chromium.org,yhirano@chromium.org,tkent@chromium.org,hiroshige@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=497933
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=199136

[hongchan, 2015-07-17 21:55:54]

Created Revert of Implement suspend() and resume() for OfflineAudioContext

[commit-bot: I haz the power, 2015-07-17 21:56:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1237383004/1

[commit-bot: I haz the power, 2015-07-17 21:57:35]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=199136

[haraken, 2015-07-18 01:14:29]

LGTM