[CSS Shapes] First line gets incorrectly adjusted in shape-inside due to rounding

[CSS Shapes] First line gets incorrectly adjusted in shape-inside due to rounding

In order to get consistent results of the first fit position of the content in shapes,
firstIncludedIntervalLogicalTop should take a FloatSize rather than LayoutSize for
minLogicalIntervalSize, because LayoutSize clamps the float value to int, when subpixel-layout
is disabled, thus firstIncludedIntervalLogicalTop could end up calculating with an unprecize
value. This change modifies firstIncludedIntervalLogicalTop to take FloatSize consistently.

Merged WebKit revision: http://trac.webkit.org/changeset/161604

BUG=333423
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=164923

[Bem Jones-Bey (adobe), 2014-01-10 17:14:41]

lgtm

[Hans Muller, 2014-01-10 17:28:10]

Converting the type of the firstIncludedIntervalLogicalTop()
Shape::minLogicalIntervalSize() parameter from LayoutSize to FloatSize sounds
like a sensible transformation to me, since sometimes the interval size's width
starts out as a float, and the Shape methods convert their parameters to floats
internally.

The use of firstPositiveWidth() from BreakingContextInlineHeaders.h is where
implicitly converting to LayoutSize and then back to float (in
firstIncludedIntervalLogicalTop) was needlessly lossy.

[leviw_travelin_and_unemployed, 2014-01-10 21:56:52]

https://codereview.chromium.org/133123003/diff/1/LayoutTests/fast/shapes/shap...
File
LayoutTests/fast/shapes/shape-inside/shape-inside-polygon-rounded-first-fit.html
(right):

https://codereview.chromium.org/133123003/diff/1/LayoutTests/fast/shapes/shap...
LayoutTests/fast/shapes/shape-inside/shape-inside-polygon-rounded-first-fit.html:35:
<p>Bug <a href="http://webkit.org/b/126601">126601</a>: [CSS Shapes] First line
gets incorrectly adjusted in shape-inside due to rounding in some polygons</p>
Can we get a crbug? :)

https://codereview.chromium.org/133123003/diff/1/Source/core/rendering/shapes...
File Source/core/rendering/shapes/ShapeInsideInfo.h (right):

https://codereview.chromium.org/133123003/diff/1/Source/core/rendering/shapes...
Source/core/rendering/shapes/ShapeInsideInfo.h:92: LayoutUnit
computeFirstFitPositionForFloat(const FloatSize) const;
I don't imagine you mean to pass this const by value.

[Zoltan, 2014-01-10 22:21:38]

Added crbug and &s.

[leviw_travelin_and_unemployed, 2014-01-10 22:23:31]

lgtm

[commit-bot: I haz the power, 2014-01-10 22:25:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zoltan@adobe.com/133123003/90001

[commit-bot: I haz the power, 2014-01-10 23:39:19]

Retried try job too often on linux_blink for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...

[commit-bot: I haz the power, 2014-01-10 23:41:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zoltan@adobe.com/133123003/90001

[commit-bot: I haz the power, 2014-01-11 02:38:10]

Change committed as 164923