[CSS Grid Layout] Use CSS_FR for flexible lengths instead of CSS_DIMENSION

[CSS Grid Layout] Use CSS_FR for flexible lengths instead of CSS_DIMENSION

Although 'fr' units are dimensions we're using a custom
CSSPrimitiveValue:UnitType which matches how px, em, ... are parsed. That's
why we should use CSS_FR instead of CSS_DIMENSION for the computed style.

This also fixes a bug in the style builder which was converting the fractional
primitive value to a float instead of a double causing rounding issues in
some tests.

BUG=235258
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=157820

[Julien - ping for review, 2013-09-13 16:44:51]

lgtm

If you are going to remove the unneeded pieces from the original patch,
CSSPrimitiveValue::isDimension() should also be removed.

https://codereview.chromium.org/23537037/diff/1/Source/core/css/CSSPrimitiveV...
File Source/core/css/CSSPrimitiveValue.cpp (right):

https://codereview.chromium.org/23537037/diff/1/Source/core/css/CSSPrimitiveV...
Source/core/css/CSSPrimitiveValue.cpp:991: // FIXME
I don't like this change, even if you are reverting the code to its original
state for one reason: the FIXME is *not actionable*. If I read it, I have no
clue what I should (or shouldn't) do.

I would just put the following instead:

// FIXME: We currently don't handle CSS_DIMENSION properly as we don't store the
actual dimension, just the numeric value as a string.

[svillar, 2013-09-13 17:29:05]

On 2013/09/13 16:44:51, Julien Chaffraix wrote:
> lgtm
> 
> If you are going to remove the unneeded pieces from the original patch,
> CSSPrimitiveValue::isDimension() should also be removed.

Indeed

>
https://codereview.chromium.org/23537037/diff/1/Source/core/css/CSSPrimitiveV...
> File Source/core/css/CSSPrimitiveValue.cpp (right):
> 
>
https://codereview.chromium.org/23537037/diff/1/Source/core/css/CSSPrimitiveV...
> Source/core/css/CSSPrimitiveValue.cpp:991: // FIXME
> I don't like this change, even if you are reverting the code to its original
> state for one reason: the FIXME is *not actionable*. If I read it, I have no
> clue what I should (or shouldn't) do.
> 
> I would just put the following instead:
> 
> // FIXME: We currently don't handle CSS_DIMENSION properly as we don't store
the
> actual dimension, just the numeric value as a string.

Yeah you're right, the FIXME alone says nothing

[commit-bot: I haz the power, 2013-09-16 10:48:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/svillar@igalia.com/23537037/7001

[commit-bot: I haz the power, 2013-09-16 11:57:48]

Change committed as 157820