Improve preload related priorities

Improve preload related priorities

While testing preload, I noticed a couple of related prioritization issues
which make little sense:
* Image discovery is used as a signal "bottom of page" scripts, even if
  the image was delivered using link preload.
* Fonts are of a "very high" priority, which makes sense in their "natural"
  discovery order, but doesn't make sense for preloaded fonts, as we don't
  want them to content on bandwidth with more critical CSS and parser-blocking
  scripts.

This CL changes the above to make sure that preloaded images are not used as a
signal that scripts are "bottom page" ones, and to make sure that preloaded fonts
are of "high" priority, rather than "very high".

BUG=

Review-Url: https://codereview.chromium.org/2753053004
Cr-Commit-Position: refs/heads/master@{#458037}
Committed: https://chromium.googlesource.com/chromium/src/+/9d3f830376493925acf2e35b150b56ebcb7eeeaa

[Yoav Weiss, 2017-03-17 12:05:15]

The CQ bit was checked by yoav@yoav.ws to run a CQ dry run

[commit-bot: I haz the power, 2017-03-17 12:05:24]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Yoav Weiss, 2017-03-17 12:07:24]

yoav@yoav.ws changed reviewers:
+ csharrison@chromium.org, pmeenan@chromium.org

[Yoav Weiss, 2017-03-17 12:07:25]

Hey Pat & Charlie,

A couple of fixes for weird prioritization decisions I saw while testing
preload. They shouldn't have a wider impact, but let me know what you think.

[Pat Meenan, 2017-03-17 12:13:39]

lgtm

[commit-bot: I haz the power, 2017-03-17 13:19:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-17 13:19:01]

Dry run: This issue passed the CQ dry run.

[Charlie Harrison, 2017-03-18 01:00:19]

lgtm/2

[Yoav Weiss, 2017-03-18 07:02:01]

The CQ bit was checked by yoav@yoav.ws

[commit-bot: I haz the power, 2017-03-18 07:02:19]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-18 07:09:48]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-18 07:09:50]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Mike West, 2017-03-20 08:45:20]

mkwst@chromium.org changed reviewers:
+ mkwst@chromium.org

[Mike West, 2017-03-20 08:45:21]

RS LGTM for //platform/loader.

[Yoav Weiss, 2017-03-20 08:48:18]

The CQ bit was checked by yoav@yoav.ws

[commit-bot: I haz the power, 2017-03-20 08:48:29]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-20 11:17:32]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1489999698685980, "parent_rev":
"daab1d2d9fc143408042a22538eb988980120632", "commit_rev":
"9d3f830376493925acf2e35b150b56ebcb7eeeaa"}

[commit-bot: I haz the power, 2017-03-20 11:18:28]

Description was changed from

==========
Improve preload related priorities

While testing preload, I noticed a couple of related prioritization issues
which make little sense:
* Image discovery is used as a signal "bottom of page" scripts, even if
  the image was delivered using link preload.
* Fonts are of a "very high" priority, which makes sense in their "natural"
  discovery order, but doesn't make sense for preloaded fonts, as we don't
  want them to content on bandwidth with more critical CSS and parser-blocking
  scripts.

This CL changes the above to make sure that preloaded images are not used as a
signal that scripts are "bottom page" ones, and to make sure that preloaded
fonts
are of "high" priority, rather than "very high".

BUG=
==========

to

==========
Improve preload related priorities

While testing preload, I noticed a couple of related prioritization issues
which make little sense:
* Image discovery is used as a signal "bottom of page" scripts, even if
  the image was delivered using link preload.
* Fonts are of a "very high" priority, which makes sense in their "natural"
  discovery order, but doesn't make sense for preloaded fonts, as we don't
  want them to content on bandwidth with more critical CSS and parser-blocking
  scripts.

This CL changes the above to make sure that preloaded images are not used as a
signal that scripts are "bottom page" ones, and to make sure that preloaded
fonts
are of "high" priority, rather than "very high".

BUG=

Review-Url: https://codereview.chromium.org/2753053004
Cr-Commit-Position: refs/heads/master@{#458037}
Committed:
https://chromium.googlesource.com/chromium/src/+/9d3f830376493925acf2e35b150b...
==========

[commit-bot: I haz the power, 2017-03-20 11:18:29]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/9d3f830376493925acf2e35b150b...