Catch up the spec update in CSS Rhythmic Sizing

third_party/WebKit/Source/core/css/CSSProperties.json5

 {
 // This file specifies all the CSS properties we support and the necessary
 // information for our code generation. The various supported arguments
 // are described below with example usage
 
   parameters: {
     // - alias_for: "other-property"
     // Properties specifying alias_for should be virtually identical to the
     // properties they alias. Minor parsing differences are allowed as long as
     // the CSSValues created are of the same format of the aliased property.
@@ skipping 1599 matching lines @@
       inherited: true,
       svg: true,
     },
     {
       name: "size",
       api_class: true,
       api_methods: ["parseSingleValue"],
       custom_all: true,
     },
     {
-      name: "snap-height",
+      name: "line-height-step",

[meade_UTC10, 2017/03/06 02:40:20]

This should be in alphabetical order. Would you mind moving this up with the
rest of the l's?

[kojii, 2017/03/06 03:05:55]

Done.

       api_class: true,
       api_methods: ["parseSingleValue"],
-      custom_all: true,
+      converter: "convertComputedLength<uint8_t>",
       inherited: true,
       runtime_flag: "CSSSnapSize",
     },
     {
       name: "speak",
       inherited: true,
     },
     {
       name: "stop-color",
       api_class: "CSSPropertyAPIColor",
@@ skipping 1457 matching lines @@
     {
       name: "-webkit-transition-timing-function",
       alias_for: "transition-timing-function",
     },
     {
       name: "-webkit-user-select",
       alias_for: "user-select",
     },
   ],
 }