Blacklist low scale factors.

Blacklist low scale factors.

For any device-scaling-factor < 1.3, a device-scaling-factor of 1 will
be enforced.

This fixes blurriness with monitors that only have a slightly higher
resolution than 96 dpi, but high enough to result in a
device-scaling-factor of >1.

BUG=484400
Committed: https://crrev.com/fa30cbdf96439ea623d47d655a10962049d83b6c
Cr-Commit-Position: refs/heads/master@{#347156}

[stapelberg, 2015-08-28 14:35:23]

stapelberg@google.com changed reviewers:
+ estade@chromium.org, oshima@chromium.org

[stapelberg, 2015-08-28 14:35:23]

R=oshima for the change, R=estade for OWNERS approval

[Evan Stade, 2015-08-28 14:54:11]

lgtm from owners perspective but I haven't been following this saga too closely
so we should wait for Oshima too.

https://codereview.chromium.org/1324513002/diff/1/chrome/browser/ui/libgtk2ui...
File chrome/browser/ui/libgtk2ui/gtk2_ui.cc (right):

https://codereview.chromium.org/1324513002/diff/1/chrome/browser/ui/libgtk2ui...
chrome/browser/ui/libgtk2ui/gtk2_ui.cc:1445: return (rounded < 1.3 ? 1.0 :
rounded);
nit, no parens

[oshima, 2015-09-02 17:45:02]

lgtm

[stapelberg, 2015-09-03 13:50:52]

The CQ bit was checked by stapelberg@google.com

[stapelberg, 2015-09-03 13:50:52]

The patchset sent to the CQ was uploaded after l-g-t-m from oshima@chromium.org,
estade@chromium.org
Link to the patchset: https://codereview.chromium.org/1324513002/#ps20001
(title: "Blacklist low scale factors.")

[commit-bot: I haz the power, 2015-09-03 13:51:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1324513002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1324513002/20001

[commit-bot: I haz the power, 2015-09-03 15:00:20]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-03 15:00:56]

Patchset 2 (id:??) landed as
https://crrev.com/fa30cbdf96439ea623d47d655a10962049d83b6c
Cr-Commit-Position: refs/heads/master@{#347156}

[mario.endlessm, 2016-01-12 15:07:12]

mario@endlessm.com changed reviewers:
+ mario@endlessm.com

[mario.endlessm, 2016-01-12 15:07:12]

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
File chrome/browser/ui/libgtk2ui/gtk2_ui.cc (right):

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
chrome/browser/ui/libgtk2ui/gtk2_ui.cc:1445: return rounded < 1.3 ? 1.0 :
rounded;
Came across this patch set today and found that this comparison is not working
as intended: As 'rounded' is a float variable and the 1.3 literal is a double,
the function is returning the 1.0 "adjusted" value in those cases where
'rounded' gets set to the 1.30000 (float) value.

Thus, a quick follow-up patch to fix this to be 'rounded < 1.3f ? 1.0f :
rounded' would be nice. I can do it myself, but as it's quite trivial I thought
I would just comment here first, just in case.

[Evan Stade, 2016-01-13 04:40:13]

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
File chrome/browser/ui/libgtk2ui/gtk2_ui.cc (right):

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
chrome/browser/ui/libgtk2ui/gtk2_ui.cc:1445: return rounded < 1.3 ? 1.0 :
rounded;
Good catch.

Also, I'm not sure if this is intentional, but the CL description is slightly
inaccurate:

"For any device-scaling-factor < 1.3, a device-scaling-factor of 1 will
be enforced."

In fact, a scale factor of 1.25 will return 1.3 rather than enforcing 1 (modulo
the bug Mario points out).

[mario.endlessm, 2016-01-13 08:58:23]

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
File chrome/browser/ui/libgtk2ui/gtk2_ui.cc (right):

https://codereview.chromium.org/1324513002/diff/20001/chrome/browser/ui/libgt...
chrome/browser/ui/libgtk2ui/gtk2_ui.cc:1445: return rounded < 1.3 ? 1.0 :
rounded;
I thought the same thing too and then understood it as if it was an error in the
description (which would perhaps mean "_rounded_ device-scaling-factor"), but
perhaps it's better to use floor() instead of round() here.

[mario.endlessm, 2016-01-13 09:58:46]

Just uploaded a patch to fix the float literals for review in
https://codereview.chromium.org/1581883003