Unbundle link rel=prefetch from privacy settings

Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
Committed: https://crrev.com/3b2ebae80f0d0985148ae0478ee5dde185019669
Cr-Commit-Position: refs/heads/master@{#381046}

[pasko, 2016-03-09 19:03:34]

Description was changed from

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches even when the
setting is Off. Reason: developers should just use prefetch in all cases and
avoid coming up with 'creative' ways to prefetch in cases they are not allowed
to do so.

BUG=589369
==========

to

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: developers should just use prefetch in all cases and avoid coming up
with creative ways to prefetch in cases they are not allowed to do so.

BUG=589369
==========

[pasko, 2016-03-09 20:06:38]

Description was changed from

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: developers should just use prefetch in all cases and avoid coming up
with creative ways to prefetch in cases they are not allowed to do so.

BUG=589369
==========

to

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

[pasko, 2016-03-09 20:07:03]

Description was changed from

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

to

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

[pasko, 2016-03-09 20:07:03]

pasko@chromium.org changed reviewers:
+ gavinp@chromium.org, kenjibaheux@chromium.org

[pasko, 2016-03-09 20:13:52]

kenjibaheux: FYI
gavinp: PTaL

Some notes:

* chrome/browser/predictors are unaffected by this change

* The IsPrefetchEnabled() is used only once in
chrome_resource_dispatcher_host_delegate.cc, as well as DisableForFieldTrial().
I am tempted to inline this callchain and remove two files to reduce some
complexity. Please let me know if doing this mini-cleanup as part of this change
is preferable.

[gavinp, 2016-03-11 19:04:36]

lgtm.

You can do the cleanup or not; my slight preference is to do it, and my lgtm
applies to that too.

[pasko, 2016-03-14 18:11:29]

On 2016/03/11 19:04:36, gavinp wrote:
> lgtm.
> 
> You can do the cleanup or not; my slight preference is to do it, and my lgtm
> applies to that too.

Decided to go with the current version because:
* targeting M50, and it has already happily branched
* changes in chrome_resource_dispatcher_host_delegate.cc requires review by
"nasko (slow)" which may be slow

[pasko, 2016-03-14 18:25:54]

The CQ bit was checked by pasko@chromium.org

[commit-bot: I haz the power, 2016-03-14 18:26:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1777833003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1777833003/20001

[pasko, 2016-03-14 18:31:04]

The cleanup follows up here: https://codereview.chromium.org/1800723002/ feel
free to express your opinion on it early

[commit-bot: I haz the power, 2016-03-14 19:43:28]

Description was changed from

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

to

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

[commit-bot: I haz the power, 2016-03-14 19:43:29]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-14 19:44:37]

Description was changed from

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369
==========

to

==========
Unbundle link rel=prefetch from privacy settings

The privacy settings have the On/Off choice now saying: "Use a prediction
service to load pages quickly". Default is On.

This change allows <link rel=prefetch> to perform prefetches regardless of the
setting and network type.

Reason: web developers should be able prefetch with all possible privacy
settings and with all possible network types. This would avoid web devs coming
up with creative ways to prefetch in cases they are not allowed to do so.

Assumption: all requests arriving through ChromeResourceDispatcherHostDelegate
are initiated by the renderer, and the only way to issue a prefetch from there
is via <link rel=prefetch>.

BUG=589369

Committed: https://crrev.com/3b2ebae80f0d0985148ae0478ee5dde185019669
Cr-Commit-Position: refs/heads/master@{#381046}
==========

[commit-bot: I haz the power, 2016-03-14 19:44:38]

Patchset 2 (id:??) landed as
https://crrev.com/3b2ebae80f0d0985148ae0478ee5dde185019669
Cr-Commit-Position: refs/heads/master@{#381046}