Implement normalization for textarea "API value"

components/script/textinput.rs

@@ -770,7 +770,11 @@ impl<T: ClipboardProvider> TextInput<T> {
     /// any \n encountered will be stripped and force a new logical line.
     pub fn set_content(&mut self, content: DOMString) {
         self.lines = if self.multiline {
-            content.split('\n').map(DOMString::from).collect()
+            // https://html.spec.whatwg.org/multipage/#textarea-line-break-normalisation-transformation
+            content.replace("\r\n", "\n")
+                   .split(|c| c == '\n' || c == '\r')
+                   .map(DOMString::from)
+                   .collect()
         } else {
             vec!(content)
         };

tests/wpt/metadata/html/semantics/forms/the-textarea-element/value-defaultValue-textContent.html.ini

@@ -1,17 +1,8 @@
 [value-defaultValue-textContent.html]
   type: testharness
-  [defaultValue and value treat CRLF differently]
-    expected: FAIL
-
-  [tests for the value setter]
-    expected: FAIL
-
   [defaultValue and value are affected by textContent in combination with appending a DocumentFragment]
     expected: FAIL
 
   [defaultValue and value reflect child text content, not textContent]
     expected: FAIL
 
-  [value normalizes CRLF even spread over multiple text nodes]
-    expected: FAIL
-