The idea with this patch is that style code will first call
InlineStyleDeclarationWillChange before style declaration has changed, and SetInlineStyleDeclaration once it has changed.
In order to be able to report old attribute value, InlineStyleDeclarationWillChange reads the value and also calls AttributeWillChange (so that DOMMutationObserser can grab the old value). Later SetInlineStyleDeclaration passes the old value to
SetAttrAndNotify so that mutation events and attributeChanged callbacks are handled correctly.
Because of performance, declaration can't be cloned for reading the old value. And that is why the recently-added callback is used to detect when declaration is about to change (bug 1466963 and followup bug 1468665).
To keep the expected existing behavior, even if declaration isn't changed, but just a new declaration was created (since there wasn't any), we need to still run all these
willchange/set calls. That is when the code has 'if (created)' checks.
Since there are several declaration implementation and only nsDOMCSSAttributeDeclaration needs the about-to-change callback, GetPropertyChangeClosure is the one to initialize the callback closure, and the struct which is then passes as data to the closure.
Apparently we lost mutation event testing on style attribute when the pref was added, so test_style_attr_listener.html is modified to test both pref values.
This change stores the subject principal in the URLExtraData when parsing
style attributes, which causes it to be used as the triggering principal for
those loads rather than defaulting to the document principal.
MozReview-Commit-ID: 22tmNRRCgaj
This is necessary in order to parse style attributes using the subject
principal of the caller, rather than defaulting to the page principal.
MozReview-Commit-ID: GIshajQ28la
(Path is actually r=froydnj.)
Bug 1400459 devirtualized nsIAtom so that it is no longer a subclass of
nsISupports. This means that nsAtom is now a better name for it than nsIAtom.
MozReview-Commit-ID: 91U22X2NydP
Now that Declaration implements nsIStyleRule, we don't need the memory
overhead of storing a StyleRule object for style attributes.
We also need to change this prior to patch 5, because the changes in
patch 5 that will allow rules to change (but declarations not) would
otherwise break due to style attribute object merging done by
nsAttrValue::ParseStyleAttribute.
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
