Auto merge of #15038 - upsuper:text-decor-blink, r=emilio

Store blink value for text-decoration-line

The spec does say user agents may not blink, but it doesn't say this
value can be ignored during parsing.

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

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- [ ] These changes do not require tests because _____

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components/style/properties/gecko.mako.rs

@@ -2315,6 +2315,9 @@ fn static_assert() {
         if v.line_through {
             bits |= structs::NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH as u8;
         }
+        if v.blink {
+            bits |= structs::NS_STYLE_TEXT_DECORATION_LINE_BLINK as u8;
+        }
         self.gecko.mTextDecorationLine = bits;
     }
 

components/style/properties/longhand/text.mako.rs

@@ -117,8 +117,7 @@ ${helpers.single_keyword("unicode-bidi",
         pub underline: bool,
         pub overline: bool,
         pub line_through: bool,
-        // 'blink' is accepted in the parser but ignored.
+        pub blink: bool,
-        // Just not blinking the text is a conforming implementation per CSS 2.1.
     }
 
     impl ToCss for SpecifiedValue {
@@ -140,6 +139,13 @@ ${helpers.single_keyword("unicode-bidi",
                     try!(dest.write_str(" "));
                 }
                 try!(dest.write_str("line-through"));
+                space = true;
+            }
+            if self.blink {
+                if space {
+                    try!(dest.write_str(" "));
+                }
+                try!(dest.write_str("blink"));
             }
             Ok(())
         }
@@ -148,7 +154,7 @@ ${helpers.single_keyword("unicode-bidi",
         pub type T = super::SpecifiedValue;
         #[allow(non_upper_case_globals)]
         pub const none: T = super::SpecifiedValue {
-            underline: false, overline: false, line_through: false
+            underline: false, overline: false, line_through: false, blink: false
         };
     }
     #[inline] pub fn get_initial_value() -> computed_value::T {
@@ -157,12 +163,11 @@ ${helpers.single_keyword("unicode-bidi",
     /// none | [ underline || overline || line-through || blink ]
     pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
         let mut result = SpecifiedValue {
-            underline: false, overline: false, line_through: false,
+            underline: false, overline: false, line_through: false, blink: false
         };
         if input.try(|input| input.expect_ident_matching("none")).is_ok() {
             return Ok(result)
         }
-        let mut blink = false;
         let mut empty = true;
 
         while input.try(|input| {
@@ -174,8 +179,8 @@ ${helpers.single_keyword("unicode-bidi",
                                       else { empty = false; result.overline = true },
                         "line-through" => if result.line_through { return Err(()) }
                                           else { empty = false; result.line_through = true },
-                        "blink" => if blink { return Err(()) }
+                        "blink" => if result.blink { return Err(()) }
-                                   else { empty = false; blink = true },
+                                   else { empty = false; result.blink = true },
                         _ => return Err(())
                     }
                 } else {