Revert of Create MediaValuesCached and TokenPreloadScanner on the parser thread

Revert of Create MediaValuesCached and TokenPreloadScanner on the parser thread (patchset #5 id:80001 of https://codereview.chromium.org/1641853003/ )

Reason for revert:
Somewhat speculative; https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20Tests%20%281%29?numbuilds=200 used to be green all the time, but it started being red 70% of the time recently, with SingleProcessTracingBrowserTest.TestMemoryInfra failing. Example: https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20Tests%20%281%29/builds/23150/steps/browser_tests/logs/SingleProcessTracingBrowserTest.TestMemoryInfra

Original issue's description:
> Create MediaValuesCached and TokenPreloadScanner on the parser thread
>
> Previously, TokenPreloadScanner and MediaValuesCached were allocated on the main
> thread, passed to and intended to be destructed on the background parser thread.
> However, since https://codereview.chromium.org/1611303006, MediaValuesCached
> is an Oilpan object and started to be destructed on the main thread, which
> causes race conditions on the refcount of StringImpl in MediaValuesCachedData.
>
> This CL removes the race condition by creating, using and destructing
> TokenPreloadScanner and MediaValuesCached on the background parser thread.
> Instead of MediaValuesCached (an Oilpan object), MediaValuesCachedData
> (non-Oilpan object) is created on the main thread and passed to the background
> parser thread.
>
> This CL removes MediaValuesCached::isSafeToSendToAnotherThread() because it
> is no longer safe to be passed across threads,
> and defines CrossThreadCopier for MediaValuesCachedData instead.
>
> BUG=581565, 478194
>
> Committed: https://crrev.com/1e224f69bc03710f9f7c8c8f8d8f3526d004ea00
> Cr-Commit-Position: refs/heads/master@{#374027}

TBR=yoav@yoav.ws,haraken@chromium.org,kouhei@chromium.org,hiroshige@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=581565, 478194
Committed: https://crrev.com/f660d522b995fd7285bdbffe1edbf21ef84e8d4a
Cr-Commit-Position: refs/heads/master@{#374063}

[Nico, 2016-02-07 18:20:26]

Created Revert of Create MediaValuesCached and TokenPreloadScanner on the parser
thread

[commit-bot: I haz the power, 2016-02-07 18:20:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1679703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1679703002/1

[commit-bot: I haz the power, 2016-02-07 18:32:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1679703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1679703002/1

[commit-bot: I haz the power, 2016-02-07 19:02:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1679703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1679703002/1

[commit-bot: I haz the power, 2016-02-07 19:32:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1679703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1679703002/1

[commit-bot: I haz the power, 2016-02-07 20:01:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1679703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1679703002/1

[commit-bot: I haz the power, 2016-02-07 20:10:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-07 20:11:50]

Description was changed from

==========
Revert of Create MediaValuesCached and TokenPreloadScanner on the parser thread
(patchset #5 id:80001 of https://codereview.chromium.org/1641853003/ )

Reason for revert:
Somewhat speculative;
https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20T...
used to be green all the time, but it started being red 70% of the time
recently, with SingleProcessTracingBrowserTest.TestMemoryInfra failing. Example:
https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20T...


Original issue's description:
> Create MediaValuesCached and TokenPreloadScanner on the parser thread
> 
> Previously, TokenPreloadScanner and MediaValuesCached were allocated on the
main
> thread, passed to and intended to be destructed on the background parser
thread.
> However, since https://codereview.chromium.org/1611303006, MediaValuesCached
> is an Oilpan object and started to be destructed on the main thread, which
> causes race conditions on the refcount of StringImpl in MediaValuesCachedData.
> 
> This CL removes the race condition by creating, using and destructing
> TokenPreloadScanner and MediaValuesCached on the background parser thread.
> Instead of MediaValuesCached (an Oilpan object), MediaValuesCachedData
> (non-Oilpan object) is created on the main thread and passed to the background
> parser thread.
> 
> This CL removes MediaValuesCached::isSafeToSendToAnotherThread() because it
> is no longer safe to be passed across threads,
> and defines CrossThreadCopier for MediaValuesCachedData instead.
> 
> BUG=581565, 478194
> 
> Committed: https://crrev.com/1e224f69bc03710f9f7c8c8f8d8f3526d004ea00
> Cr-Commit-Position: refs/heads/master@{#374027}

TBR=yoav@yoav.ws,haraken@chromium.org,kouhei@chromium.org,hiroshige@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=581565, 478194
==========

to

==========
Revert of Create MediaValuesCached and TokenPreloadScanner on the parser thread
(patchset #5 id:80001 of https://codereview.chromium.org/1641853003/ )

Reason for revert:
Somewhat speculative;
https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20T...
used to be green all the time, but it started being red 70% of the time
recently, with SingleProcessTracingBrowserTest.TestMemoryInfra failing. Example:
https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20T...

Original issue's description:
> Create MediaValuesCached and TokenPreloadScanner on the parser thread
>
> Previously, TokenPreloadScanner and MediaValuesCached were allocated on the
main
> thread, passed to and intended to be destructed on the background parser
thread.
> However, since https://codereview.chromium.org/1611303006, MediaValuesCached
> is an Oilpan object and started to be destructed on the main thread, which
> causes race conditions on the refcount of StringImpl in MediaValuesCachedData.
>
> This CL removes the race condition by creating, using and destructing
> TokenPreloadScanner and MediaValuesCached on the background parser thread.
> Instead of MediaValuesCached (an Oilpan object), MediaValuesCachedData
> (non-Oilpan object) is created on the main thread and passed to the background
> parser thread.
>
> This CL removes MediaValuesCached::isSafeToSendToAnotherThread() because it
> is no longer safe to be passed across threads,
> and defines CrossThreadCopier for MediaValuesCachedData instead.
>
> BUG=581565, 478194
>
> Committed: https://crrev.com/1e224f69bc03710f9f7c8c8f8d8f3526d004ea00
> Cr-Commit-Position: refs/heads/master@{#374027}

TBR=yoav@yoav.ws,haraken@chromium.org,kouhei@chromium.org,hiroshige@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=581565, 478194

Committed: https://crrev.com/f660d522b995fd7285bdbffe1edbf21ef84e8d4a
Cr-Commit-Position: refs/heads/master@{#374063}
==========

[commit-bot: I haz the power, 2016-02-07 20:11:51]

Patchset 1 (id:??) landed as
https://crrev.com/f660d522b995fd7285bdbffe1edbf21ef84e8d4a
Cr-Commit-Position: refs/heads/master@{#374063}