Don't lower priority for scripts inserted by doc.write

Don't lower priority for scripts inserted by doc.write

HTML Chunks inserted by document.write() are run through a separate
instance of the preload scanner from the main document.  If the main
document scanner has already discovered an image then all scripts
discovered by any preload scanner regardless of where they came from
would be considered late-body.

This behavior causes a regression where a document.write() in the head
that includes multiple script tags will discover them but treat them as
late-body scripts and only load them one at a time.

BUG=713727, 712338
Review-Url: https://codereview.chromium.org/2841363002
Cr-Commit-Position: refs/heads/master@{#467672}
(cherry picked from commit 591cbec71ef07912c8c7d2b0acc1efb25196d7f1)

Review-Url: https://codereview.chromium.org/2862303002 .
Cr-Commit-Position: refs/branch-heads/3071@{#420}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/d255072f8bf07ba7b1058fa6d9a5943d43cbeaef

[Pat Meenan, 2017-05-05 17:42:18]

Description was changed from

==========
Don't lower priority for scripts inserted by doc.write

HTML Chunks inserted by document.write() are run through a separate
instance of the preload scanner from the main document.  If the main
document scanner has already discovered an image then all scripts
discovered by any preload scanner regardless of where they came from
would be considered late-body.

This behavior causes a regression where a document.write() in the head
that includes multiple script tags will discover them but treat them as
late-body scripts and only load them one at a time.

BUG=713727, 712338
Review-Url: https://codereview.chromium.org/2841363002
Cr-Commit-Position: refs/heads/master@{#467672}
(cherry picked from commit 591cbec71ef07912c8c7d2b0acc1efb25196d7f1)
==========

to

==========
Don't lower priority for scripts inserted by doc.write

HTML Chunks inserted by document.write() are run through a separate
instance of the preload scanner from the main document.  If the main
document scanner has already discovered an image then all scripts
discovered by any preload scanner regardless of where they came from
would be considered late-body.

This behavior causes a regression where a document.write() in the head
that includes multiple script tags will discover them but treat them as
late-body scripts and only load them one at a time.

BUG=713727, 712338
Review-Url: https://codereview.chromium.org/2841363002
Cr-Commit-Position: refs/heads/master@{#467672}
(cherry picked from commit 591cbec71ef07912c8c7d2b0acc1efb25196d7f1)

Review-Url: https://codereview.chromium.org/2862303002 .
Cr-Commit-Position: refs/branch-heads/3071@{#420}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/d255072f8bf07ba7b1058fa6d9a5...
==========

[Pat Meenan, 2017-05-05 17:42:19]

Committed patchset #1 (id:1) manually as
d255072f8bf07ba7b1058fa6d9a5943d43cbeaef.