Fix a crash in HttpVaryData::MatchesRequests.

Fix a crash in HttpVaryData::MatchesRequests.

crbug.com/469675 remove an implicit Vary: Cookie for redirected
requests. But some cached redirected requests could still have
HttpVaryData::is_valid_ == true.

Therefore some requests could reach a NOTREACHED() in
HttpVaryData::MatchesRequests() because comparing an HTTP request
vary that have a HttpVaryData::Init() now returning false because
no Vary from the request with a previously cached HttpVaryRequest
that have is_valid_ == true.

BUG=611575
Committed: https://crrev.com/7ec544a858f4dd2b5b3a0ad0949a1f24f55f10b4
Cr-Commit-Position: refs/heads/master@{#395317}

[gabadie, 2016-05-23 08:27:33]

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

[commit-bot: I haz the power, 2016-05-23 08:27:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2000123002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2000123002/1

[gabadie, 2016-05-23 08:28:36]

gabadie@chromium.org changed reviewers:
+ gavinp@chromium.org

[gabadie, 2016-05-23 08:28:36]

Hey Gavin,

Here is the crash workaround in HttpVaryData::MatchesRequests. PTAL.

[gabadie, 2016-05-23 08:32:12]

On 2016/05/23 08:28:36, gabadie wrote:
> Hey Gavin,
> 
> Here is the crash workaround in HttpVaryData::MatchesRequests. PTAL.

I think a proper fix would be to replace the HttpVaryData::MatchesRequest() with
a HttpVaryData::Compare(), so that the Init is done by the user of HttpVaryData.
But this CL's purpose is to fix the issue quickly.

[commit-bot: I haz the power, 2016-05-23 10:59:40]

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

[commit-bot: I haz the power, 2016-05-23 10:59:41]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[gavinp, 2016-05-23 11:37:35]

lgtm

https://codereview.chromium.org/2000123002/diff/1/net/http/http_vary_data.cc
File net/http/http_vary_data.cc (right):

https://codereview.chromium.org/2000123002/diff/1/net/http/http_vary_data.cc#...
net/http/http_vary_data.cc:71: // This case can happen if <this> was loaded from
a cache that was populated
Nit: |this|

[gavinp, 2016-05-23 11:43:22]

It does make me sad that we're throwing away all these perfectly usable cached
entries; but it's only once, and the result is a better cache afterwards... So
it's OK.

[gabadie, 2016-05-23 13:00:43]

On 2016/05/23 11:43:22, gavinp wrote:
> It does make me sad that we're throwing away all these perfectly usable cached
> entries; but it's only once, and the result is a better cache afterwards... So
> it's OK.

Thanks Gavin! Addressed your nit in the new revision. Landing! :)

[gabadie, 2016-05-23 13:00:47]

The CQ bit was checked by gabadie@chromium.org

[gabadie, 2016-05-23 13:00:48]

The patchset sent to the CQ was uploaded after l-g-t-m from gavinp@chromium.org
Link to the patchset: https://codereview.chromium.org/2000123002/#ps20001
(title: "Addresses Gavin's nit")

[commit-bot: I haz the power, 2016-05-23 13:01:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2000123002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2000123002/20001

[commit-bot: I haz the power, 2016-05-23 14:20:53]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-05-23 14:23:25]

Description was changed from

==========
Fix a crash in HttpVaryData::MatchesRequests.

crbug.com/469675 remove an implicit Vary: Cookie for redirected
requests. But some cached redirected requests could still have
HttpVaryData::is_valid_ == true.

Therefore some requests could reach a NOTREACHED() in
HttpVaryData::MatchesRequests() because comparing an HTTP request
vary that have a HttpVaryData::Init() now returning false because
no Vary from the request with a previously cached HttpVaryRequest
that have is_valid_ == true.

BUG=611575
==========

to

==========
Fix a crash in HttpVaryData::MatchesRequests.

crbug.com/469675 remove an implicit Vary: Cookie for redirected
requests. But some cached redirected requests could still have
HttpVaryData::is_valid_ == true.

Therefore some requests could reach a NOTREACHED() in
HttpVaryData::MatchesRequests() because comparing an HTTP request
vary that have a HttpVaryData::Init() now returning false because
no Vary from the request with a previously cached HttpVaryRequest
that have is_valid_ == true.

BUG=611575

Committed: https://crrev.com/7ec544a858f4dd2b5b3a0ad0949a1f24f55f10b4
Cr-Commit-Position: refs/heads/master@{#395317}
==========

[commit-bot: I haz the power, 2016-05-23 14:23:26]

Patchset 2 (id:??) landed as
https://crrev.com/7ec544a858f4dd2b5b3a0ad0949a1f24f55f10b4
Cr-Commit-Position: refs/heads/master@{#395317}