We previously didn't do this because we relied on our anonymous wrapper
to perform transforms. However, that resulted in only the children
transforming, and the frame's cliprect wouldn't be updated,
giving the impression of the z-ordering being wrong.
Also adds reftests from the relevant BZ bug found later.
Resolves#2355
* Part 1. Move IsLocalRefURL to nsContentUtils to reuse this function. (port-rewrite)
`IsLocalRefURL` is originally designed to be used by URLValue only.
Since we need this function in SVGUseElement::LookupHref too, move it to nsContentUtils as a util function.
* Revert "Part 1. Move IsLocalRefURL to nsContentUtils to reuse this function. (port-rewrite)"
This reverts commit 19f010c62022e269f99066a8d90e3522fe31adaf.
* Part 1. Duplicate IsLocalRefURL to nsContentUtils to reuse this function.
`IsLocalRefURL` is originally designed to be used by URLValue only.
Since we need this function in SVGUseElement::LookupHref too, duplicate it to nsContentUtils as a util function.
This is a duplication because CSSValue uses stringbuffers and not nsStrings.
While Bug 1356060 - "Just use nsString in URLValueData" converts this use from stringbuffer to nsString, it builds on a bunch of vartype refactoring (nsString vs. nsAString, etc.) which is too much of a headache to deal with just to deduplicate this simple function.
* Part 2. Implement nsSVGEffects::GetBaseURLForLocalRef to export local-ref-url-resolving logic.
ResolveURLUsingLocalRef is designed to be internally used by nsSVGEffects::Get-{SVGEffect}-URI functions.
Since we also need it in SVGUseElement::LookupHref, make it public in nsSVGEffects.
* Part 3. Resolve local-ref in SVGUseElement::LookupHref by nsSVGEffects::GetBaseURLForLocalRef.
* Part 4. Reftest for using local-ref as xlink:href value.
