Fix incorrect style recalculation of text-decoration properties.

Fix incorrect style recalculation of text-decoration properties.

This change adds the color and style of each decoration to the
AppliedTextDecoration class. This is needed to make RenderStyle
diffs compute correctly when the color or style of a decoration is changed.

The color-resolving code in RenderObject has been moved to RenderStyle to
enable use from both RenderStyle and RenderObject.

This patch also makes it possible to implement multiple decorations
on the same line. (A future patch).

BUG=350840, 315271
TEST=text-decoration-color-recalc.html
     text-decoration-style-recalc.html
     text-decoration-line-recalc.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=174285

[Julien - ping for review, 2014-05-19 10:30:17]

lgtm

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
File Source/core/rendering/style/AppliedTextDecoration.h (right):

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
Source/core/rendering/style/AppliedTextDecoration.h:22: bool isSimple() const {
return m_style == TextDecorationStyleSolid && m_color.isCurrentColor(); }
We should disambiguate this function: it only makes sense on Underline so we
should make this clear by changing the name to isSimpleUnderline(). Furthermore
we either enforce the assumption via an ASSERT or just add the appropriate text
decoration check. I prefer the second option but could live with the first.

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
File Source/core/rendering/style/RenderStyle.cpp (right):

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
Source/core/rendering/style/RenderStyle.cpp:1439: if
(!styleColor.isCurrentColor())
Shouldn't we also make sure that |styleColor| is not fully transparent here too?

[andersr, 2014-05-19 12:54:02]

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
File Source/core/rendering/style/AppliedTextDecoration.h (right):

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
Source/core/rendering/style/AppliedTextDecoration.h:22: bool isSimple() const {
return m_style == TextDecorationStyleSolid && m_color.isCurrentColor(); }
On 2014/05/19 10:30:18, Julien Chaffraix - CET wrote:
> We should disambiguate this function: it only makes sense on Underline so we
> should make this clear by changing the name to isSimpleUnderline().
Furthermore
> we either enforce the assumption via an ASSERT or just add the appropriate
text
> decoration check. I prefer the second option but could live with the first.

Done.

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
File Source/core/rendering/style/RenderStyle.cpp (right):

https://codereview.chromium.org/280503003/diff/1/Source/core/rendering/style/...
Source/core/rendering/style/RenderStyle.cpp:1439: if
(!styleColor.isCurrentColor())
On 2014/05/19 10:30:18, Julien Chaffraix - CET wrote:
> Shouldn't we also make sure that |styleColor| is not fully transparent here
too?

Hmm, I don't think so, because then we would fall back to
strokeColor/fillColor/currentColor even when the author explicitly sets
'text-decoration-color: transparent'.

[andersr, 2014-05-19 12:54:12]

The CQ bit was checked by andersr@opera.com

[commit-bot: I haz the power, 2014-05-19 12:54:28]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/andersr@opera.com/280503003/40001

[commit-bot: I haz the power, 2014-05-19 14:11:36]

Change committed as 174285