style: Make word-break: break-word behave like word-break: normal; overflow-wrap: anywhere.

Differential Revision: https://phabricator.services.mozilla.com/D21398

components/style/cbindgen.toml

@@ -95,6 +95,7 @@ include = [
   "Perspective",
   "ZIndex",
   "TransformOrigin",
+  "WordBreak",
 ]
 item_types = ["enums", "structs", "typedefs"]
 

components/style/properties/data.py

@@ -347,6 +347,7 @@ class Longhand(object):
                 "TouchAction",
                 "TransformStyle",
                 "UserSelect",
+                "WordBreak",
                 "XSpan",
                 "XTextZoom",
                 "ZIndex",

components/style/properties/gecko.mako.rs

@@ -1328,6 +1328,7 @@ impl Clone for ${style_struct.gecko_struct_name} {
         "TransformOrigin": impl_simple,
         "UserSelect": impl_simple,
         "url::UrlOrNone": impl_css_url,
+        "WordBreak": impl_simple,
         "ZIndex": impl_simple,
     }
 

components/style/properties/longhands/inherited_text.mako.rs

@@ -74,13 +74,13 @@ ${helpers.predefined_type(
     servo_restyle_damage="rebuild_and_reflow",
 )}
 
-// TODO(pcwalton): Support `word-break: keep-all` once we have better CJK support.
+${helpers.predefined_type(
-${helpers.single_keyword(
     "word-break",
-    "normal break-all keep-all",
+    "WordBreak",
-    gecko_constant_prefix="NS_STYLE_WORDBREAK",
+    "computed::WordBreak::Normal",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text/#propdef-word-break",
+    needs_context=False,
     servo_restyle_damage="rebuild_and_reflow",
 )}
 

components/style/values/computed/mod.rs

@@ -78,7 +78,7 @@ pub use self::svg::{SVGLength, SVGOpacity, SVGPaint, SVGPaintKind};
 pub use self::svg::{SVGPaintOrder, SVGStrokeDashArray, SVGWidth};
 pub use self::table::XSpan;
 pub use self::text::{InitialLetter, LetterSpacing, LineHeight};
-pub use self::text::{OverflowWrap, TextOverflow, WordSpacing};
+pub use self::text::{OverflowWrap, TextOverflow, WordSpacing, WordBreak};
 pub use self::text::{TextAlign, TextEmphasisPosition, TextEmphasisStyle};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, Transform, TransformOperation};

components/style/values/computed/text.rs

@@ -17,7 +17,7 @@ use crate::values::{CSSFloat, CSSInteger};
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ToCss};
 
-pub use crate::values::specified::OverflowWrap;
+pub use crate::values::specified::{OverflowWrap, WordBreak};
 pub use crate::values::specified::TextAlignKeyword as TextAlign;
 pub use crate::values::specified::TextEmphasisPosition;
 

components/style/values/specified/mod.rs

@@ -80,7 +80,7 @@ pub use self::svg::{SVGPaintOrder, SVGStrokeDashArray, SVGWidth};
 pub use self::svg_path::SVGPathData;
 pub use self::table::XSpan;
 pub use self::text::{InitialLetter, LetterSpacing, LineHeight, TextAlign};
-pub use self::text::{OverflowWrap, TextEmphasisPosition, TextEmphasisStyle};
+pub use self::text::{OverflowWrap, TextEmphasisPosition, TextEmphasisStyle, WordBreak};
 pub use self::text::{TextAlignKeyword, TextDecorationLine, TextOverflow, WordSpacing};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, Transform};

components/style/values/specified/text.rs

@@ -813,6 +813,32 @@ impl From<TextEmphasisPosition> for u8 {
     }
 }
 
+/// Values for the `word-break` property.
+#[repr(u8)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+)]
+#[allow(missing_docs)]
+pub enum WordBreak {
+    Normal,
+    BreakAll,
+    KeepAll,
+    /// The break-word value, needed for compat.
+    ///
+    /// Specifying `word-break: break-word` makes `overflow-wrap` behave as
+    /// `anywhere`, and `word-break` behave like `normal`.
+    BreakWord,
+}
+
 /// Values for the `overflow-wrap` property.
 #[repr(u8)]
 #[derive(