Bug 1302949 - Add a method to parse a property-value pair into a declaration block; r=Manishearth

The property may be a shorthand property in which case the declaration block
will contain the expanded longhand properties and values.

MozReview-Commit-ID: KxqlYgbIZqL

tests/unit/stylo/Cargo.toml

@@ -13,6 +13,7 @@ doctest = false
 
 [dependencies]
 app_units = "0.3"
+cssparser = {version = "0.7"}
 env_logger = "0.3"
 euclid = "0.10.1"
 lazy_static = "0.2"

tests/unit/stylo/lib.rs

@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 extern crate app_units;
+extern crate cssparser;
 extern crate env_logger;
 extern crate euclid;
 extern crate geckoservo;