Auto merge of #11428 - g-k:csstext, r=SimonSapin

csstext

- [x] These changes fix #4431.
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy --faster` reports one error for the `css_properties_accessors!` macro not having a spec link

```
$ git log -1 --format=oneline
91fb9bf1d388c3ede304a5d649dd21fe975787b0 fixup! implement cssText
$ ./mach build -d
   Compiling style v0.0.1 (file:///Users/greg/servo/components/style)
   Compiling gfx v0.0.1 (file:///Users/greg/servo/components/gfx)
   Compiling script v0.0.1 (file:///Users/greg/servo/components/script)
   Compiling layout_traits v0.0.1 (file:///Users/greg/servo/components/layout_traits)
   Compiling compositing v0.0.1 (file:///Users/greg/servo/components/compositing)
   Compiling glutin_app v0.0.1 (file:///Users/greg/servo/ports/glutin)
   Compiling constellation v0.0.1 (file:///Users/greg/servo/components/constellation)
   Compiling layout v0.0.1 (file:///Users/greg/servo/components/layout)
   Compiling servo v0.0.1 (file:///Users/greg/servo/components/servo)
Build completed in 0:05:11.475584
$ ./mach test-tidy --faster
Checking files for tidiness...
./components/script/dom/cssstyledeclaration.rs:386: method declared in webidl is missing a comment with a specification link
  Progress: 100% (12/12)
```

- [x] There are tests for these changes.  More CSSOM tests pass, but others fail that probably shouldn't:

* `./mach test-css tests/wpt/css-tests/cssom-1_dev/html/index-002.htm` and a bunch of the other tests in `/css-tests/cssom-1_dev/html/ crash when run individually
* `./mach test-css tests/wpt/css-tests/cssom-1_dev/html/cssom-cssText-serialize.htm` fails to strip a trailing semicolon (`left: 10px` vs `left: 10px;`)
* `./mach test-css tests/wpt/css-tests/cssom-1_dev/html/index-001.htm` shared shorthand values aren't coalesced (`margin: 20px` vs. `margin: 20px 20px 20px 20px`)
* `./mach test-css tests/wpt/css-tests/cssom-1_dev/html/cssstyledeclaration-csstext.htm` also crashes and fails for `color: red;` vs. `color: RED;`,  preserving declaration insertion order, whitespace in the value, and setting an unknown style property.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11428)
<!-- Reviewable:end -->

1 files changed, 2 insertions, 2 deletions

diff --git a/components/script/dom/webidls/CSSStyleDeclaration.webidl b/components/script/dom/webidls/CSSStyleDeclaration.webidl
index 1d1d5223183..cf7c3ade7f2 100644
--- a/components/script/dom/webidls/CSSStyleDeclaration.webidl
+++ b/components/script/dom/webidls/CSSStyleDeclaration.webidl
@@ -9,8 +9,8 @@
  */
 
 interface CSSStyleDeclaration {
-  //[SetterThrows]
-  //         attribute DOMString cssText;
+  [SetterThrows]
+           attribute DOMString cssText;
   readonly attribute unsigned long length;
   getter DOMString item(unsigned long index);
   DOMString getPropertyValue(DOMString property);