Enabled use of FontFamily enum type
https://github.com/servo/servo/issues/8371
In addition to replacing loose strings with the FontFamily enum in `font_cache_task.rs`, I also centralized the add_generic_font calls into one single function. If centralizing into one function is not desired or if anything else needs to be changed, please let me know.
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Properly propagate changes when range or trees are mutated
Does the same thing as #6817, but storing Range instances directly in their start and end containers.
Cc @dzbarsky
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Updated string_cache, html5ever, xml5ever and selectors in Cargo.toml files and Cargo.lock.
Removed references to string_cache_plugin.
Import atom! and ns! from string_cache.
Replaced ns!("") by ns!().
Replaced ns!(XML) and co by ns!(xml) and co.
Replaced atom!(foo) by atom!("foo").
Replaced Atom::from_slice by Atom::from.
Replaced atom.as_slice() by &*atom.
This is the strategy we'll need to take for attributes, and so this change
puts us in a position to handle attributes and state the same way.
This does mean that we stop taking care to track the situations where our
state has reverted to the original state, with no net change. I think that's
probably of negligible value though.
This should make it somewhat easier to experiment with alternative
representations in the future. To reduce churn, this commit leaves the String
field public, though.
Also, this will allow us to use the default String type to represent the IDL
USVString type, which explicitly forbids unpaired surrogates, ans as such is
a better match to the Rust String type.
Implementing activation behavior for <label>
Attempt to resolve#8179
@Manishearth , could you give me some resources having more information about what each function in `Activatable` does? The code compiles on my machine but I guess a lot more is needed
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