Extract trial tokens using <meta http-equiv>

Extract trial tokens using <meta http-equiv>

In addition to meta tags, the Experimental Framework will eventually
support providing trial tokens via an HTTP header. With support for an
HTTP header, it makes sense for the meta tag to use the http-equiv
attribute.

This CL changes the EF to use the http-equiv attribute, instead of the
name attribute, to extract meta tags with trial tokens. The support for
HTTP headers will not be included in M51. However, we want to avoid
launching the EF in M50, then changing the expected meta tag format in
M51+.

The logic for extracting meta tags was already covered by automated
tests (both unit and layout).

BUG=590349
Committed: https://crrev.com/312c8c52c920d2df5f3ca33bff03c159b9db257b
Cr-Commit-Position: refs/heads/master@{#379306}

[chasej, 2016-03-02 20:05:08]

chasej@chromium.org changed reviewers:
+ iclelland@chromium.org

[chasej, 2016-03-02 20:05:09]

iclelland, please take a look.

[iclelland, 2016-03-02 22:56:33]

lgtm with one nit

https://codereview.chromium.org/1756193002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp
(right):

https://codereview.chromium.org/1756193002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp:42: if
(equalIgnoringCase(metaElement->httpEquiv(), kTrialMetaTagName)) {
nit; Should probably change the name of kTrialMetaTagName to something like
kTrialHeaderName

[chasej, 2016-03-03 06:20:48]

https://codereview.chromium.org/1756193002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp
(right):

https://codereview.chromium.org/1756193002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp:42: if
(equalIgnoringCase(metaElement->httpEquiv(), kTrialMetaTagName)) {
On 2016/03/02 22:56:33, iclelland wrote:
> nit; Should probably change the name of kTrialMetaTagName to something like
> kTrialHeaderName

Done.

[chasej, 2016-03-03 06:26:21]

chasej@chromium.org changed reviewers:
+ jbroman@chromium.org

[chasej, 2016-03-03 06:26:22]

jbroman, please take a look.

[jbroman, 2016-03-03 15:08:41]

https://codereview.chromium.org/1756193002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp
(right):

https://codereview.chromium.org/1756193002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp:20: const
char kTrialHeaderName[] = "origin-trials";
Is this going to be the actual HTTP header name, or will you have to change it
anyhow (to X-Origin-Trials, or something else, as bug 582045 alludes to?).

The explanation given in the CL description is that we don't want the format of
the meta tag to change, but I think that's only true if the http-equiv header
name also doesn't change.

[chasej, 2016-03-03 16:24:28]

On 2016/03/03 15:08:41, jbroman wrote:
>
https://codereview.chromium.org/1756193002/diff/20001/third_party/WebKit/Sour...
> File third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp
> (right):
> 
>
https://codereview.chromium.org/1756193002/diff/20001/third_party/WebKit/Sour...
> third_party/WebKit/Source/core/origin_trials/OriginTrialContext.cpp:20: const
> char kTrialHeaderName[] = "origin-trials";
> Is this going to be the actual HTTP header name, or will you have to change it
> anyhow (to X-Origin-Trials, or something else, as bug 582045 alludes to?).
> 
> The explanation given in the CL description is that we don't want the format
of
> the meta tag to change, but I think that's only true if the http-equiv header
> name also doesn't change.

I don't expect the header name to change from "origin-trials". You're correct
that bug 582045 is ambiguous on the naming. There is a discussion about the
http-equiv change, and the appropriate naming for the header. That discussion
was kind of ambiguous on the naming as well. I've now made it explicit, and
updated the related bugs:
https://groups.google.com/a/chromium.org/forum/?pli=1#!topic/experimentation-...

[jbroman, 2016-03-03 16:27:12]

thanks, lgtm

[chasej, 2016-03-04 17:28:57]

The CQ bit was checked by chasej@chromium.org

[chasej, 2016-03-04 17:28:58]

The patchset sent to the CQ was uploaded after l-g-t-m from
iclelland@chromium.org, jbroman@chromium.org
Link to the patchset: https://codereview.chromium.org/1756193002/#ps40001
(title: "Change header name to singular 'origin-trial'")

[commit-bot: I haz the power, 2016-03-04 17:29:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1756193002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1756193002/40001

[commit-bot: I haz the power, 2016-03-04 17:35:16]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-03-04 17:36:23]

Description was changed from

==========
Extract trial tokens using <meta http-equiv>

In addition to meta tags, the Experimental Framework will eventually
support providing trial tokens via an HTTP header. With support for an
HTTP header, it makes sense for the meta tag to use the http-equiv
attribute.

This CL changes the EF to use the http-equiv attribute, instead of the
name attribute, to extract meta tags with trial tokens. The support for
HTTP headers will not be included in M51. However, we want to avoid
launching the EF in M50, then changing the expected meta tag format in
M51+.

The logic for extracting meta tags was already covered by automated
tests (both unit and layout).

BUG=590349
==========

to

==========
Extract trial tokens using <meta http-equiv>

In addition to meta tags, the Experimental Framework will eventually
support providing trial tokens via an HTTP header. With support for an
HTTP header, it makes sense for the meta tag to use the http-equiv
attribute.

This CL changes the EF to use the http-equiv attribute, instead of the
name attribute, to extract meta tags with trial tokens. The support for
HTTP headers will not be included in M51. However, we want to avoid
launching the EF in M50, then changing the expected meta tag format in
M51+.

The logic for extracting meta tags was already covered by automated
tests (both unit and layout).

BUG=590349

Committed: https://crrev.com/312c8c52c920d2df5f3ca33bff03c159b9db257b
Cr-Commit-Position: refs/heads/master@{#379306}
==========

[commit-bot: I haz the power, 2016-03-04 17:36:24]

Patchset 3 (id:??) landed as
https://crrev.com/312c8c52c920d2df5f3ca33bff03c159b9db257b
Cr-Commit-Position: refs/heads/master@{#379306}