Bug 1286337 - Part 2. Update initial_values of background and mask in property_database.js r=heycam

MozReview-Commit-ID: CgRUeCphr17

--HG--
extra : rebase_source : 48de097b3ea8b6beb2e0c62d4026b8a469233670

layout/style/test/property_database.js

@@ -2143,7 +2143,8 @@ var gCSSProperties = {
     subproperties: [ "background-attachment", "background-color", "background-image", "background-position-x", "background-position-y", "background-repeat", "background-clip", "background-origin", "background-size" ],
     initial_values: [ "transparent", "none", "repeat", "scroll", "0% 0%", "top left", "left top", "0% 0% / auto", "top left / auto", "left top / auto", "0% 0% / auto auto",
       "transparent none", "top left none", "left top none", "none left top", "none top left", "none 0% 0%", "left top / auto none", "left top / auto auto none",
-      "transparent none repeat scroll top left", "left top repeat none scroll transparent", "transparent none repeat scroll top left / auto", "left top / auto repeat none scroll transparent", "none repeat scroll 0% 0% / auto auto transparent" ],
+      "transparent none repeat scroll top left", "left top repeat none scroll transparent", "transparent none repeat scroll top left / auto", "left top / auto repeat none scroll transparent", "none repeat scroll 0% 0% / auto auto transparent",
+      "padding-box border-box" ],
     other_values: [
         /* without multiple backgrounds */
       "green",
@@ -6881,7 +6882,8 @@ if (SupportsMaskShorthand()) {
     subproperties: ["mask-clip", "mask-image", "mask-mode", "mask-origin", "mask-position-x", "mask-position-y", "mask-repeat", "mask-size" , "mask-composite"],
     initial_values: [ "match-source", "none", "repeat", "add", "0% 0%", "top left", "left top", "0% 0% / auto", "top left / auto", "left top / auto", "0% 0% / auto auto",
       "top left none", "left top none", "none left top", "none top left", "none 0% 0%", "left top / auto none", "left top / auto auto none",
-      "match-source none repeat add top left", "left top repeat none add", "none repeat add top left / auto", "left top / auto repeat none add match-source", "none repeat add 0% 0% / auto auto match-source" ],
+      "match-source none repeat add top left", "left top repeat none add", "none repeat add top left / auto", "left top / auto repeat none add match-source", "none repeat add 0% 0% / auto auto match-source",
+      "border-box", "border-box border-box" ],
     other_values: [
       "none alpha repeat add left top",
       "url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAIAAAD8GO2jAAAAKElEQVR42u3NQQ0AAAgEoNP+nTWFDzcoQE1udQQCgUAgEAgEAsGTYAGjxAE/G/Q2tQAAAABJRU5ErkJggg==)",