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

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

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.
-${helpers.single_keyword(
+${helpers.predefined_type(
     "word-break",
-    "normal break-all keep-all",
-    gecko_constant_prefix="NS_STYLE_WORDBREAK",
+    "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",
 )}