predictors: Key the resource prefetcher by URL, not navigation.

predictors: Key the resource prefetcher by URL, not navigation.

The resource prefetcher is currently keyed by navigation. It is now
keyed by URL, which is the only piece of data used from the
navigation. Aside from less coupling, this opens the door to trigger
prefetches before a navigation starts.

This commit also removes the possibility of having two concurrent
prefetches running for the same host. Aside from being rare, this is not
desirable as a lot of resources are expected to be shared across two
URLs on the same domain. Thus, a prefetch B can unintentionally use a
resource prefetched by a prefetch A from the same domain, negating the
prefetch (since LOAD_PREFETCH resources can only be used once without
revalidation).

BUG=631966
Committed: https://crrev.com/72fec99e143cd8fa697e04ad32bc6be4dc9c6c8e
Cr-Commit-Position: refs/heads/master@{#420898}

[Benoit L, 2016-09-26 09:52:55]

lizeb@chromium.org changed reviewers:
+ pasko@chromium.org

[pasko, 2016-09-26 14:37:31]

lgtm!

[Benoit L, 2016-09-26 14:38:47]

The CQ bit was checked by lizeb@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-26 14:39:14]

Dry run: 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, 2016-09-26 15:58:35]

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

[commit-bot: I haz the power, 2016-09-26 15:58:35]

Dry run: This issue passed the CQ dry run.

[Benoit L, 2016-09-26 15:59:19]

The CQ bit was checked by lizeb@chromium.org

[commit-bot: I haz the power, 2016-09-26 15:59:46]

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, 2016-09-26 16:05:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-26 16:07:51]

Description was changed from

==========
predictors: Key the resource prefetcher by URL, not navigation.

The resource prefetcher is currently keyed by navigation. It is now
keyed by URL, which is the only piece of data used from the
navigation. Aside from less coupling, this opens the door to trigger
prefetches before a navigation starts.

This commit also removes the possibility of having two concurrent
prefetches running for the same host. Aside from being rare, this is not
desirable as a lot of resources are expected to be shared across two
URLs on the same domain. Thus, a prefetch B can unintentionally use a
resource prefetched by a prefetch A from the same domain, negating the
prefetch (since LOAD_PREFETCH resources can only be used once without
revalidation).

BUG=631966
==========

to

==========
predictors: Key the resource prefetcher by URL, not navigation.

The resource prefetcher is currently keyed by navigation. It is now
keyed by URL, which is the only piece of data used from the
navigation. Aside from less coupling, this opens the door to trigger
prefetches before a navigation starts.

This commit also removes the possibility of having two concurrent
prefetches running for the same host. Aside from being rare, this is not
desirable as a lot of resources are expected to be shared across two
URLs on the same domain. Thus, a prefetch B can unintentionally use a
resource prefetched by a prefetch A from the same domain, negating the
prefetch (since LOAD_PREFETCH resources can only be used once without
revalidation).

BUG=631966

Committed: https://crrev.com/72fec99e143cd8fa697e04ad32bc6be4dc9c6c8e
Cr-Commit-Position: refs/heads/master@{#420898}
==========

[commit-bot: I haz the power, 2016-09-26 16:07:53]

Patchset 1 (id:??) landed as
https://crrev.com/72fec99e143cd8fa697e04ad32bc6be4dc9c6c8e
Cr-Commit-Position: refs/heads/master@{#420898}