Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed tasks.

Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed tasks. (patchset #13 id:240001 of https://codereview.chromium.org/563203002/)

Reason for revert:
I suspect this CL caused fast/workers/worker-close.html to crash on Linux ASAN build.  Revert to confirm.

Original issue's description:
> [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed tasks.
> 
> This CL has the Blink side changes to cancel extra delayed tasks posted
> in WorkerSharedTimer. Previously extra tasks were being posted and allowed
> to complete if multiple interval timers were scheduled on worker threads.
> Now we will cancel any extra delayed task, made redundant due to newly scheduled
> lesser timer interval tasks.
> 
> BUG=410786
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182930

TBR=jochen@chromium.org,mayurk.vk@samsung.com
NOTREECHECKS=true
NOTRY=true
BUG=410786
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182981

[Zhenyao Mo, 2014-09-30 21:10:07]

Created Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed
tasks.

[commit-bot: I haz the power, 2014-09-30 21:11:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/617023003/1

[commit-bot: I haz the power, 2014-09-30 21:12:19]

Committed patchset #1 (id:1) as 182981

[Mayur Kankanwadi, 2014-10-01 05:39:23]

On 2014/09/30 21:10:07, Zhenyao Mo wrote:
> Created Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed
> tasks.

Hi Zhenyao,
Can you let me know where can I see the Linux ASAN report for the
fast/workers/worker-close.html crash.
Once I have the report, I will then start investigating the issue further.
Thanks.

[jochen (gone - plz use gerrit), 2014-10-01 06:46:15]

On 2014/10/01 at 05:39:23, mayurk.vk wrote:
> On 2014/09/30 21:10:07, Zhenyao Mo wrote:
> > Created Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra delayed
> > tasks.
> 
> Hi Zhenyao,
> Can you let me know where can I see the Linux ASAN report for the
fast/workers/worker-close.html crash.
> Once I have the report, I will then start investigating the issue further.
> Thanks.

https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...

[Zhenyao Mo, 2014-10-01 16:46:29]

On 2014/10/01 06:46:15, jochen wrote:
> On 2014/10/01 at 05:39:23, mayurk.vk wrote:
> > On 2014/09/30 21:10:07, Zhenyao Mo wrote:
> > > Created Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra
delayed
> > > tasks.
> > 
> > Hi Zhenyao,
> > Can you let me know where can I see the Linux ASAN report for the
> fast/workers/worker-close.html crash.
> > Once I have the report, I will then start investigating the issue further.
> > Thanks.
> 
>
https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...

Here is how to build a ASAN build on Linux:
http://www.chromium.org/developers/testing/addresssanitizer

It's easy to reproduce the crash with your CL.

[Mayur Kankanwadi, 2014-10-06 05:37:36]

On 2014/10/01 16:46:29, Zhenyao Mo wrote:
> On 2014/10/01 06:46:15, jochen wrote:
> > On 2014/10/01 at 05:39:23, mayurk.vk wrote:
> > > On 2014/09/30 21:10:07, Zhenyao Mo wrote:
> > > > Created Revert of [Blink-WebWorkers] WorkerSharedTimer cancels extra
> delayed
> > > > tasks.
> > > 
> > > Hi Zhenyao,
> > > Can you let me know where can I see the Linux ASAN report for the
> > fast/workers/worker-close.html crash.
> > > Once I have the report, I will then start investigating the issue further.
> > > Thanks.
> > 
> >
>
https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...
> 
> Here is how to build a ASAN build on Linux:
> http://www.chromium.org/developers/testing/addresssanitizer
> 
> It's easy to reproduce the crash with your CL.

I have added fix in the original CL.
Thanks.