Adding a metric to track only the checkerboarding.

Adding a metric to track only the checkerboarding.

BUG=466867
Committed: https://crrev.com/73a470e3f6319b170f5a60823e9e3787ec711600
Cr-Commit-Position: refs/heads/master@{#322396}

[cblume, 2015-03-17 23:33:10]

cblume@chromium.org changed reviewers:
+ aelias@chromium.org, ernstm@chromium.org, jdduke@chromium.org

[cblume, 2015-03-17 23:39:51]

cblume@chromium.org changed reviewers:
+ enne@chromium.org

[cblume, 2015-03-19 01:58:46]

This new metric tracks checkerboarding. It is similar to
mean_pixels_approximated. However, mean_pixels_approximated combines
checkerboarding and low res tiles.

I ran this new metric against smoothness.top_25_smooth and another pageset which
is in a separate CL, https://codereview.chromium.org/999243003/ . Both ran on a
Nexus 5. And both showed an exact match between mean_pixels_approximated and
this checkerboarding metric. This is a clue that we may be able to disable low
res tiles. More testing is necessary to see if that clue hold true enough to
take action.

[enne (OOO), 2015-03-19 18:02:20]

cc lgtm

Getting rid of low res if we can sounds excellent.  My memory is that the last
time we thought about removing this, danakj experimented and discovered that it
still appeared to make a difference on an N10.

[cblume, 2015-03-21 03:39:48]

On 2015/03/19 18:02:20, enne wrote:
> cc lgtm
> 
> Getting rid of low res if we can sounds excellent.  My memory is that the last
> time we thought about removing this, danakj experimented and discovered that
it
> still appeared to make a difference on an N10.

I ran smoothness.top_25_smooth on a Nexus 10 and sure enough, there is a
difference:

Avg mean_pixels_approximated: 0.207600%
Sd mean_pixels_approximated: 0.351748%

Avg mean_pixels_checkerboarded: 0.028720%
Sd mean_pixels_checkerboarded: 0.060610%

The amount of low res seems small. However, compared to checkerboarding it is
huge.
On Monday, I'll take a look at how it feels.


Here is the breakdown:

https://www.google.com/#hl=en&q=barack+obama
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
https://mail.google.com/mail
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
https://www.google.com/calendar
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
https://www.google.com/search?q=cats&tbm=isch
	mean_pixels_approximated: 0.92%
	mean_pixels_checkerboarded: 0.065%
Docs
	mean_pixels_approximated: 0.025%
	mean_pixels_checkerboarded: 0.0%
https://plus.google.com/110031535020051778989/posts
	mean_pixels_approximated: 0.563%
	mean_pixels_checkerboarded: 0.079%
http://www.youtube.com
	mean_pixels_approximated: 0.056%
	mean_pixels_checkerboarded: 0.054%
Blogger
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
Wordpress
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
Facebook
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
LinkedIn
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
Wikipedia
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
Twitter
	mean_pixels_approximated: 0.107%
	mean_pixels_checkerboarded: 0.009%
Pinterest
	mean_pixels_approximated: 0.283%
	mean_pixels_checkerboarded: 0.0%
ESPN
	mean_pixels_approximated: 1.169%
	mean_pixels_checkerboarded: 0.253%
Weather.com
	mean_pixels_approximated: 0.594%
	mean_pixels_checkerboarded: 0.155%
http://games.yahoo.com
	mean_pixels_approximated: 0.196%
	mean_pixels_checkerboarded: 0.083%
http://news.yahoo.com
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
http://www.cnn.com
	mean_pixels_approximated: 0.016%
	mean_pixels_checkerboarded: 0.0%
http://www.amazon.com
	mean_pixels_approximated: 0.056%
	mean_pixels_checkerboarded: 0.0%
http://www.ebay.com
	mean_pixels_approximated: 0.186%
	mean_pixels_checkerboarded: 0.0%
http://booking.com
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
http://answers.yahoo.com
	mean_pixels_approximated: 0.0%
	mean_pixels_checkerboarded: 0.0%
http://sports.yahoo.com
	mean_pixels_approximated: 0.025%
	mean_pixels_checkerboarded: 0.0%
http://techcrunch.com
	mean_pixels_approximated: 0.996%
	mean_pixels_checkerboarded: 0.02%

[cblume, 2015-03-24 00:55:53]

cblume@chromium.org changed reviewers:
+ nednguyen@google.com

[cblume, 2015-03-24 00:55:54]

I had added ernstm as a reviewer for src/tools/telemetry since he was in the
OWNERS file and also edited a lot of the files I had changed (and specifically,
areas around where I made changes).

However, I just noticed he is listed under emeritus and so I think I should get
a new reviewer for those changed files.

I am adding Ned for that reason.

[nednguyen, 2015-03-25 21:06:31]

On 2015/03/24 00:55:54, cblume wrote:
> I had added ernstm as a reviewer for src/tools/telemetry since he was in the
> OWNERS file and also edited a lot of the files I had changed (and
specifically,
> areas around where I made changes).
> 
> However, I just noticed he is listed under emeritus and so I think I should
get
> a new reviewer for those changed files.
> 
> I am adding Ned for that reason.

Can you move telemetry/ changes to a different patch?

[cblume, 2015-03-25 23:55:35]

On 2015/03/25 21:06:31, nednguyen wrote:
> On 2015/03/24 00:55:54, cblume wrote:
> > I had added ernstm as a reviewer for src/tools/telemetry since he was in the
> > OWNERS file and also edited a lot of the files I had changed (and
> specifically,
> > areas around where I made changes).
> > 
> > However, I just noticed he is listed under emeritus and so I think I should
> get
> > a new reviewer for those changed files.
> > 
> > I am adding Ned for that reason.
> 
> Can you move telemetry/ changes to a different patch?

I can move the telemetry/ changed to a different patch, yes.
Although, they require the changes in cc/ .
I suspect I should be checking the Chromium version from within the telemetry
changes to make sure it supports this new metric. I also suspect separating
telemetry/ changes was your gentle hint about checking versions. :)

[nednguyen, 2015-03-26 00:38:46]

On 2015/03/25 23:55:35, cblume wrote:
> On 2015/03/25 21:06:31, nednguyen wrote:
> > On 2015/03/24 00:55:54, cblume wrote:
> > > I had added ernstm as a reviewer for src/tools/telemetry since he was in
the
> > > OWNERS file and also edited a lot of the files I had changed (and
> > specifically,
> > > areas around where I made changes).
> > > 
> > > However, I just noticed he is listed under emeritus and so I think I
should
> > get
> > > a new reviewer for those changed files.
> > > 
> > > I am adding Ned for that reason.
> > 
> > Can you move telemetry/ changes to a different patch?
> 
> I can move the telemetry/ changed to a different patch, yes.
> Although, they require the changes in cc/ .
> I suspect I should be checking the Chromium version from within the telemetry
> changes to make sure it supports this new metric. I also suspect separating
> telemetry/ changes was your gentle hint about checking versions. :)

Yeah :)

[cblume, 2015-03-26 00:59:21]

On 2015/03/26 00:38:46, nednguyen wrote:
> On 2015/03/25 23:55:35, cblume wrote:
> > On 2015/03/25 21:06:31, nednguyen wrote:
> > > On 2015/03/24 00:55:54, cblume wrote:
> > > > I had added ernstm as a reviewer for src/tools/telemetry since he was in
> the
> > > > OWNERS file and also edited a lot of the files I had changed (and
> > > specifically,
> > > > areas around where I made changes).
> > > > 
> > > > However, I just noticed he is listed under emeritus and so I think I
> should
> > > get
> > > > a new reviewer for those changed files.
> > > > 
> > > > I am adding Ned for that reason.
> > > 
> > > Can you move telemetry/ changes to a different patch?
> > 
> > I can move the telemetry/ changed to a different patch, yes.
> > Although, they require the changes in cc/ .
> > I suspect I should be checking the Chromium version from within the
telemetry
> > changes to make sure it supports this new metric. I also suspect separating
> > telemetry/ changes was your gentle hint about checking versions. :)
> 
> Yeah :)

They have been moved to https://codereview.chromium.org/1033733010 where I will
now begin checking for Chrome branch number.

[cblume, 2015-03-26 16:20:42]

The CQ bit was checked by cblume@chromium.org

[cblume, 2015-03-26 16:20:43]

The patchset sent to the CQ was uploaded after l-g-t-m from enne@chromium.org
Link to the patchset: https://codereview.chromium.org/1010323002/#ps120001
(title: "Forgot to remove a change from a telemetry file.")

[commit-bot: I haz the power, 2015-03-26 16:20:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1010323002/120001

[commit-bot: I haz the power, 2015-03-26 16:25:10]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2015-03-26 16:26:09]

Patchset 7 (id:??) landed as
https://crrev.com/73a470e3f6319b170f5a60823e9e3787ec711600
Cr-Commit-Position: refs/heads/master@{#322396}