Instrumenting URLRequestJob::Read to find jank

Instrumenting URLRequestJob::Read to find jank.

Prior instrumentations showed that most of jank (13.3) comes from URLRequestJob::Read.

BUG=423948
Committed: https://crrev.com/9167e6426cbf1c5b0b2944060fc8d572acaea95b
Cr-Commit-Position: refs/heads/master@{#308108}

[vadimt, 2014-12-11 20:31:54]

vadimt@chromium.org changed reviewers:
+ mmenke@chromium.org

[vadimt, 2014-12-11 20:31:55]

mmenke@, please review

[mmenke, 2014-12-12 15:23:46]

LGTM, modulo optional comment.

https://codereview.chromium.org/790723004/diff/1/net/url_request/url_request_...
File net/url_request/url_request_job.cc (right):

https://codereview.chromium.org/790723004/diff/1/net/url_request/url_request_...
net/url_request/url_request_job.cc:95: FROM_HERE_WITH_EXPLICIT_FUNCTION("423948
URLRequestJob::Read1"));
Suggest putting one in ReadRawDataHelper instead (ReadFilteredData feeds into
it, so putting one at the start of ReadRawData means URLRequestJob::Read2 would
just measure the filter time, while the one in ReadRawData would measure the
time spent by the embedder actually dealing with that data.

[vadimt, 2014-12-12 15:34:50]

https://codereview.chromium.org/790723004/diff/1/net/url_request/url_request_...
File net/url_request/url_request_job.cc (right):

https://codereview.chromium.org/790723004/diff/1/net/url_request/url_request_...
net/url_request/url_request_job.cc:95: FROM_HERE_WITH_EXPLICIT_FUNCTION("423948
URLRequestJob::Read1"));
On 2014/12/12 15:23:46, mmenke wrote:
> Suggest putting one in ReadRawDataHelper instead (ReadFilteredData feeds into
> it, so putting one at the start of ReadRawData means URLRequestJob::Read2
would
> just measure the filter time, while the one in ReadRawData would measure the
> time spent by the embedder actually dealing with that data.

Done.

[vadimt, 2014-12-12 15:34:53]

The CQ bit was checked by vadimt@chromium.org

[commit-bot: I haz the power, 2014-12-12 15:35:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/790723004/20001

[mmenke, 2014-12-12 15:45:51]

On 2014/12/12 15:35:22, I haz the power (commit-bot) wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/790723004/20001

Oops..was thinking of NotifyReadComplete, so my comment was wrong...Fortunately,
the modification I suggestion, while it doesn't actually help, doesn't break
anything, so still LGTM.  Sorry about that.

[vadimt, 2014-12-12 16:02:31]

The CQ bit was unchecked by vadimt@chromium.org

[vadimt, 2014-12-12 16:04:40]

Done

[vadimt, 2014-12-12 16:04:44]

The CQ bit was checked by vadimt@chromium.org

[commit-bot: I haz the power, 2014-12-12 16:06:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/790723004/40001

[commit-bot: I haz the power, 2014-12-12 17:18:12]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-12-12 17:19:09]

Patchset 3 (id:??) landed as
https://crrev.com/9167e6426cbf1c5b0b2944060fc8d572acaea95b
Cr-Commit-Position: refs/heads/master@{#308108}