Merge CSSSVGDocumentValue with CSSURIValue
These two CSSValue classes are used to represent the same semantic,
which is a reference to an element by means of a "url(...)" function.
CSSSVGDocumentValue carries additional state to be able to handle
references to external documents, by caching a DocumentResource.
Move all the DocumentResource state to CSSURIValue, while also keeping
the naming of the URL string (m_url). Also do some minor cleanup, for
instance by removing "SVG" from the cachedSVGDocument() method name and
dropping some unnecessary .get()s.
This bloats CSSURIValue a bit for the cases where the DocumentResource
is not utilized, but this bloat will be reduced (in relative terms) with
future developments. On the "pro"-side is naturally that we now don't
have to extend two CSSValue classes with additional functionality and
state.
BUG=470608, 405315
Review-Url: https://codereview.chromium.org/2165833006
Cr-Commit-Position: refs/heads/master@{#407126}
13 files changed
