Add revalidation_only option to precache config.

Add revalidation_only option to precache config.

When specified, resources are only fetched over the network if they have
an existing cache entry with revalidation headers. This serves as a
lower-bound approximation of the efficacy of a client-only wifi precache
mechanism, as it is limited to URLs that are only on the client AND in
the manifests.

BUG=679533
Review-Url: https://codereview.chromium.org/2614403003
Cr-Commit-Position: refs/heads/master@{#442999}
Committed: https://chromium.googlesource.com/chromium/src/+/8586921e08baafc1209e66223d0642d6246094b9

[twifkak, 2017-01-10 00:10:58]

twifkak@chromium.org changed reviewers:
+ bengr@chromium.org

[twifkak, 2017-01-10 00:10:58]

Hi Ben - sorry to bother you with this, but Jose is on vacation until Jan 16,
and I'm hoping to merge-request it, so the sooner the better.

[twifkak, 2017-01-10 00:30:27]

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

[commit-bot: I haz the power, 2017-01-10 00:31:16]

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, 2017-01-10 02:53:22]

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

[commit-bot: I haz the power, 2017-01-10 02:53:22]

Dry run: This issue passed the CQ dry run.

[bengr, 2017-01-11 20:08:46]

lgtm modulo comment requests.

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
File components/precache/core/precache_fetcher.h (right):

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
components/precache/core/precache_fetcher.h:303: bool revalidation_only);
Please add a description of parameters to the method comment.

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
components/precache/core/precache_fetcher.h:332: const bool revalidation_only_;
is_resource_request_, max_bytes_, and revalidation_only aren't obviously self
descriptive. Please add commments.

[twifkak, 2017-01-11 20:40:15]

Thanks! Submitting.

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
File components/precache/core/precache_fetcher.h (right):

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
components/precache/core/precache_fetcher.h:303: bool revalidation_only);
On 2017/01/11 20:08:46, bengr wrote:
> Please add a description of parameters to the method comment.

Done.

https://codereview.chromium.org/2614403003/diff/1/components/precache/core/pr...
components/precache/core/precache_fetcher.h:332: const bool revalidation_only_;
On 2017/01/11 20:08:46, bengr wrote:
> is_resource_request_, max_bytes_, and revalidation_only aren't obviously self
> descriptive. Please add commments.

OK, added parameter comments to the constructor, and a one-liner here to refer
to the constructor.

[twifkak, 2017-01-11 20:40:22]

The CQ bit was checked by twifkak@chromium.org

[twifkak, 2017-01-11 20:40:23]

The patchset sent to the CQ was uploaded after l-g-t-m from bengr@chromium.org
Link to the patchset: https://codereview.chromium.org/2614403003/#ps20001
(title: "Add Fetcher constructor parameter comments.")

[commit-bot: I haz the power, 2017-01-11 20:41:04]

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, 2017-01-11 21:58:02]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1484167222963470,
"parent_rev": "29140a418ac170e40b978cee388163cca308b723", "commit_rev":
"8586921e08baafc1209e66223d0642d6246094b9"}

[commit-bot: I haz the power, 2017-01-11 21:58:38]

Description was changed from

==========
Add revalidation_only option to precache config.

When specified, resources are only fetched over the network if they have
an existing cache entry with revalidation headers. This serves as a
lower-bound approximation of the efficacy of a client-only wifi precache
mechanism, as it is limited to URLs that are only on the client AND in
the manifests.

BUG=679533
==========

to

==========
Add revalidation_only option to precache config.

When specified, resources are only fetched over the network if they have
an existing cache entry with revalidation headers. This serves as a
lower-bound approximation of the efficacy of a client-only wifi precache
mechanism, as it is limited to URLs that are only on the client AND in
the manifests.

BUG=679533

Review-Url: https://codereview.chromium.org/2614403003
Cr-Commit-Position: refs/heads/master@{#442999}
Committed:
https://chromium.googlesource.com/chromium/src/+/8586921e08baafc1209e66223d06...
==========

[commit-bot: I haz the power, 2017-01-11 21:58:39]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/8586921e08baafc1209e66223d06...