Add UMA histogram DomDistiller.Time.DistillPage

Add UMA histogram DomDistiller.Time.DistillPage

This measures time spent in DistillPageImpl(), which is mostly
ExecuteJavaScript(). This includes JavaScript compilation and execution.

We already have DomDistiller.Time.DistillationTotal, but it is measured
within JavaScript.

Committed: https://crrev.com/9a2dbf2bd195dff3f420084a6fab3277ca6c9158
Cr-Commit-Position: refs/heads/master@{#329472}

[wychen, 2015-05-07 23:17:31]

wychen@chromium.org changed reviewers:
+ cjhopman@chromium.org

[wychen, 2015-05-07 23:17:31]

PTAL

[cjhopman, 2015-05-08 01:31:40]

lgtm

https://codereview.chromium.org/1131493005/diff/1/components/dom_distiller/co...
File components/dom_distiller/core/distiller_page.h (right):

https://codereview.chromium.org/1131493005/diff/1/components/dom_distiller/co...
components/dom_distiller/core/distiller_page.h:69: base::TimeTicks
distillation_start;
nit: should end with an underscore

[wychen, 2015-05-08 22:47:12]

The CQ bit was checked by wychen@chromium.org

[wychen, 2015-05-08 22:47:12]

The patchset sent to the CQ was uploaded after l-g-t-m from
cjhopman@chromium.org
Link to the patchset: https://codereview.chromium.org/1131493005/#ps20001
(title: "fix naming")

[commit-bot: I haz the power, 2015-05-08 22:54:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131493005/20001

[commit-bot: I haz the power, 2015-05-09 03:29:32]

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

[commit-bot: I haz the power, 2015-05-09 03:29:33]

Try jobs failed on following builders:
  android_chromium_gn_compile_dbg on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  cast_shell_android on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  cast_shell_linux on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  chromium_presubmit on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  linux_chromium_asan_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_chromeos_compile_dbg_ng on tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_clobber_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_gn_dbg on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  linux_chromium_gn_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)

[wychen, 2015-05-09 13:35:28]

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

[commit-bot: I haz the power, 2015-05-09 13:36:18]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131493005/20001

[commit-bot: I haz the power, 2015-05-09 17:40:38]

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

[commit-bot: I haz the power, 2015-05-09 17:40:40]

Dry run: Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)

[wychen, 2015-05-11 17:40:35]

wychen@chromium.org changed reviewers:
+ mpearson@google.com

[wychen, 2015-05-11 17:40:36]

+mpearson for histograms.xml owner review.

[Mark P, 2015-05-11 18:27:10]

mpearson@chromium.org changed reviewers:
+ mpearson@chromium.org

[Mark P, 2015-05-11 18:27:11]

histograms.xml lgtm

https://codereview.chromium.org/1131493005/diff/20001/components/dom_distille...
File components/dom_distiller/core/distiller_page.cc (right):

https://codereview.chromium.org/1131493005/diff/20001/components/dom_distille...
components/dom_distiller/core/distiller_page.cc:117: VLOG(1) <<
"DomDistiller.Time.DistillPage = " << distillation_time;
minor comment: do you actually need these VLOGs are were they just meant for
debugging on your own machine?

[wychen, 2015-05-11 20:42:50]

https://codereview.chromium.org/1131493005/diff/20001/components/dom_distille...
File components/dom_distiller/core/distiller_page.cc (right):

https://codereview.chromium.org/1131493005/diff/20001/components/dom_distille...
components/dom_distiller/core/distiller_page.cc:117: VLOG(1) <<
"DomDistiller.Time.DistillPage = " << distillation_time;
On 2015/05/11 18:27:10, Mark P wrote:
> minor comment: do you actually need these VLOGs are were they just meant for
> debugging on your own machine?

Thanks for your review! I used LOG(ERROR) locally for debugging, and converted
to VLOG(1) so that it is not shown by default, and is kept for future
references. I think VLOG(1 or larger) should be suitable for low volume
debugging like this one.

Ref:
https://sites.google.com/a/google.com/chromeos-team-tok/how-to/debugging-tips
https://sites.google.com/a/google.com/googletv/Home/engineering/platform/chro...
https://groups.google.com/a/google.com/forum/#!msg/chromoting/vmHfJ_5KeWk/BLh...

[wychen, 2015-05-12 19:14:41]

The CQ bit was checked by wychen@chromium.org

[commit-bot: I haz the power, 2015-05-12 19:16:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131493005/20001

[commit-bot: I haz the power, 2015-05-12 20:14:54]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-12 20:15:40]

Patchset 2 (id:??) landed as
https://crrev.com/9a2dbf2bd195dff3f420084a6fab3277ca6c9158
Cr-Commit-Position: refs/heads/master@{#329472}