Add flag to enable alternative services.

Add flag to enable alternative services.

Add command line flag and about:flags flag to enable alternative services.  See
https://crrev.com/1303273002#msg3 for motivation.

BUG=392575
Committed: https://crrev.com/886e6d53c89372695fe41ce9775780ca036fa43a
Cr-Commit-Position: refs/heads/master@{#348893}

[Bence, 2015-09-03 16:32:21]

bnc@chromium.org changed reviewers:
+ rch@chromium.org

[Bence, 2015-09-03 16:32:22]

Ryan: PTAL.  Thanks.

[Ryan Hamilton, 2015-09-08 17:50:06]

Looks good. Two small comments.

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
File chrome/browser/io_thread.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
chrome/browser/io_thread.cc:1165:
ShouldQuicEnableAlternativeServices(quic_trial_params);
Typically, we put the command line flag logic into the ShouldEnable method. Can
you do that?

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
File chrome/browser/io_thread_unittest.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
chrome/browser/io_thread_unittest.cc:210:
EXPECT_TRUE(params.use_alternative_services);
Oh, interesting. Is this behavior we're expecting to make use of?

https://codereview.chromium.org/1309363003/diff/20001/chrome/common/chrome_sw...
File chrome/common/chrome_switches.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/common/chrome_sw...
chrome/common/chrome_switches.cc:517: const char kEnableAltSvc[]                
 = "enable-alternative-services";
Since the flag is --enable-alternative-services, I suspect the variable should
be kEnableAlternativeServices.

[Bence, 2015-09-14 21:56:16]

PTAL.  Thanks.

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
File chrome/browser/io_thread.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
chrome/browser/io_thread.cc:1165:
ShouldQuicEnableAlternativeServices(quic_trial_params);
On 2015/09/08 17:50:06, Ryan Hamilton wrote:
> Typically, we put the command line flag logic into the ShouldEnable method.
Can
> you do that?

Done.

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
File chrome/browser/io_thread_unittest.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/browser/io_threa...
chrome/browser/io_thread_unittest.cc:210:
EXPECT_TRUE(params.use_alternative_services);
On 2015/09/08 17:50:06, Ryan Hamilton wrote:
> Oh, interesting. Is this behavior we're expecting to make use of?

I really do not know.  There is nothing QUIC-specific about alternative
services, they could be used with other protocols like HTTP/2 as well.  But if
you want, I can gate |use_alternative_services| on |enable_quic|.  I do not have
a preference.

https://codereview.chromium.org/1309363003/diff/20001/chrome/common/chrome_sw...
File chrome/common/chrome_switches.cc (right):

https://codereview.chromium.org/1309363003/diff/20001/chrome/common/chrome_sw...
chrome/common/chrome_switches.cc:517: const char kEnableAltSvc[]                
 = "enable-alternative-services";
On 2015/09/08 17:50:06, Ryan Hamilton wrote:
> Since the flag is --enable-alternative-services, I suspect the variable should
> be kEnableAlternativeServices.

Done.

[Ryan Hamilton, 2015-09-14 23:27:30]

lgtm

[Bence, 2015-09-15 13:43:03]

bnc@chromium.org changed reviewers:
+ asvitkine@chromium.org

[Bence, 2015-09-15 13:43:03]

Alexei: PTAL at tools/metrics/histograms/histogram.xml.  Thank you.

[Alexei Svitkine (slow), 2015-09-15 15:13:29]

lgtm

[Bence, 2015-09-15 15:27:54]

The CQ bit was checked by bnc@chromium.org

[commit-bot: I haz the power, 2015-09-15 15:28:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1309363003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1309363003/60001

[commit-bot: I haz the power, 2015-09-15 15:33:39]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-09-15 15:34:40]

Patchset 4 (id:??) landed as
https://crrev.com/886e6d53c89372695fe41ce9775780ca036fa43a
Cr-Commit-Position: refs/heads/master@{#348893}

[commit-bot: I haz the power, 2015-09-23 12:45:16]

Patchset 4 (id:??) landed as
https://crrev.com/886e6d53c89372695fe41ce9775780ca036fa43a
Cr-Commit-Position: refs/heads/master@{#348893}