Change WokerThread to use a blink::WebThread

Change WokerThread to use a blink::WebThread

This is a reland of https://codereview.chromium.org/400153002/ in which I forgot the remove the changes made to WebThread for shared timer. The first patch set is equivalent to the previous CL.

BUG=301515
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179217

[nasko, 2014-07-30 06:53:26]

Hey Jochen,
Can you review this CL? First patch is equivalent to the original CL I had and
the second one is reverting the changes made to WebThread.
Thanks in advance!
Nasko

[jochen (gone - plz use gerrit), 2014-07-30 09:29:47]

lgtm

[nasko, 2014-07-30 09:34:49]

The CQ bit was checked by nasko@chromium.org

[commit-bot: I haz the power, 2014-07-30 09:34:58]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/nasko@chromium.org/423303004/20001

[commit-bot: I haz the power, 2014-07-30 09:38:31]

Change committed as 179217

[alancutter (OOO until 2018), 2014-07-31 04:00:03]

A revert of this CL has been created in
https://codereview.chromium.org/432673003/ by alancutter@chromium.org.

The reason for reverting is: This change introduced leaks that were detected in
the following layout tests:
fast/workers/worker-terminate.html
({"numberOfLiveDocuments":[1,2],"numberOfLiveNodes":[4,21]})
inspector-protocol/debugger/debugger-terminate-dedicated-worker-while-paused.html
({"numberOfLiveDocuments":[1,2],"numberOfLiveNodes":[4,32]})

http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Leak/bu....