Revert of BackgroundHTMLParser: Introduce ParsedChunkQueue to pass ParsedChunks to main thread

Revert of BackgroundHTMLParser: Introduce ParsedChunkQueue to pass ParsedChunks to main thread (patchset #6 id:100001 of https://codereview.chromium.org/1394663004/ )

Reason for revert:
Failed MSAN: http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20MSan%20Tests/builds/10886/steps/browser_tests/logs/CaptivePortalBrowserTest.GoBackToTimeout

Original issue's description:
> BackgroundHTMLParser: Introduce ParsedChunkQueue to pass ParsedChunks to main thread
>
> Before this CL, each ParsedChunk from the background parser thread was
> posted as separate tasks, which wasted time in main thread on poor CPU
> devices (esp. mobiles).
>
> This CL attempts to minimize postTask by passing ParsedChunks via
> introduced ParsedChunkQueue class and only using postTask to notify
> that it is not empty.
>
> BUG=540988
>
> Committed: https://crrev.com/63f797324ae8302ddd405bf4f7b9a03ca3926f8d
> Cr-Commit-Position: refs/heads/master@{#356261}

TBR=kinuko@chromium.org,tzik@chromium.org,yoav@yoav.ws,esprehn@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=540988
Committed: https://crrev.com/19f48bfcf83b34f0b54c41252d357e44a4857272
Cr-Commit-Position: refs/heads/master@{#356271}

[kouhei (in TOK), 2015-10-27 11:58:17]

Created Revert of BackgroundHTMLParser: Introduce ParsedChunkQueue to pass
ParsedChunks to main thread

[commit-bot: I haz the power, 2015-10-27 11:58:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1422233002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1422233002/1

[commit-bot: I haz the power, 2015-10-27 11:59:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-27 11:59:34]

Patchset 1 (id:??) landed as
https://crrev.com/19f48bfcf83b34f0b54c41252d357e44a4857272
Cr-Commit-Position: refs/heads/master@{#356271}