style: Also move page-break-inside outside of mako.

Differential Revision: https://phabricator.services.mozilla.com/D11876

components/style/properties/data.py

@@ -292,6 +292,7 @@ class Longhand(object):
                 "AlignSelf",
                 "Appearance",
                 "BreakBetween",
+                "BreakWithin",
                 "BackgroundRepeat",
                 "BorderImageRepeat",
                 "BorderStyle",

components/style/properties/gecko.mako.rs

@@ -1397,6 +1397,7 @@ impl Clone for ${style_struct.gecko_struct_name} {
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
         "BreakBetween": impl_simple,
+        "BreakWithin": impl_simple,
         "Color": impl_color,
         "ColorOrAuto": impl_color,
         "GreaterThanOrEqualToOneNumber": impl_simple,

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

@@ -457,12 +457,13 @@ ${helpers.predefined_type(
     animation_value_type="discrete",
 )}
 
-${helpers.single_keyword(
+${helpers.predefined_type(
     "page-break-inside",
-    "auto avoid",
-    products="gecko",
+    "BreakWithin",
+    "computed::BreakWithin::Auto",
     gecko_ffi_name="mBreakInside",
-    gecko_constant_prefix="NS_STYLE_PAGE_BREAK",
+    needs_context=False,
+    products="gecko",
     spec="https://drafts.csswg.org/css2/page.html#propdef-page-break-inside",
     animation_value_type="discrete",
 )}