Auto merge of #15289 - montrivo:webidl-exposed, r=cbrewster

Expose interfaces only where they should be. #12415 - Partial

<!-- Please describe your changes on the following line: -->

I verified the following interfaces:
CSSStyleDeclaration.webidl
ElementCSSInlineStyle.webidl
ElementContentEditable.webidl
EventHandler.webidl
Screen.webidl
StyleSheetList.webidl
StyleSheet.webidl
Client.webidl

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #12415 (github issue number if applicable).

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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/script/dom/webidls/CSSStyleDeclaration.webidl

@@ -8,7 +8,7 @@
  * Copyright © 2013 W3C® (MIT, ERCIM, Keio, Beihang), All Rights Reserved.
  */
 
-[Exposed=(Window, Worker)]
+[Exposed=Window]
 interface CSSStyleDeclaration {
   [SetterThrows]
            attribute DOMString cssText;