Fix computation of animated transform w/ different from/to transform types

Fix computation of animated transform w/ different from/to transform types

Calculating the animated value between two transforms of differing types
would give random results (and ASSERT in debug.)
Fix by requiring the effective 'from' value to have the same type as the
'to' value. If the types are not the same, then use a "zero transform" as
the 'from' value.

Also adjust the behavior of animateTransform additive to-animations in
this case by clearing the list in these cases too (matching Presto and
Gecko in this particular case.)

BUG=231409
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176193

[pdr., 2014-06-13 17:29:41]

LGTM

It's unfortunate we have so many of these slightly different variations of
calculateAnimatedValue. I checked the others and it looks like TransformList is
the only class that needs this special type handling.

https://codereview.chromium.org/330813002/diff/10001/Source/core/svg/SVGTrans...
File Source/core/svg/SVGTransformList.cpp (right):

https://codereview.chromium.org/330813002/diff/10001/Source/core/svg/SVGTrans...
Source/core/svg/SVGTransformList.cpp:335: RefPtr<SVGTransform> effectiveToAtEnd
= !toAtEndOfDurationList->isEmpty() ? toAtEndOfDurationList->at(0) :
SVGTransform::create(toTransform->transformType(),
SVGTransform::ConstructZeroTransform);
Can you assert here that the transform types are the same?

[fs, 2014-06-16 08:13:49]

https://codereview.chromium.org/330813002/diff/10001/Source/core/svg/SVGTrans...
File Source/core/svg/SVGTransformList.cpp (right):

https://codereview.chromium.org/330813002/diff/10001/Source/core/svg/SVGTrans...
Source/core/svg/SVGTransformList.cpp:335: RefPtr<SVGTransform> effectiveToAtEnd
= !toAtEndOfDurationList->isEmpty() ? toAtEndOfDurationList->at(0) :
SVGTransform::create(toTransform->transformType(),
SVGTransform::ConstructZeroTransform);
On 2014/06/13 17:29:41, pdr wrote:
> Can you assert here that the transform types are the same?

SVGTransformDistance::addSVGTransforms() asserts that, so that should be covered
already I think.

[fs, 2014-06-16 08:15:20]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2014-06-16 08:16:44]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/fs@opera.com/330813002/10001

[commit-bot: I haz the power, 2014-06-16 09:06:26]

Change committed as 176193