--- a/layout/style/nsCSSPropAliasList.h
+++ b/layout/style/nsCSSPropAliasList.h
@@ -348,16 +348,67 @@ CSS_PROP_ALIAS(-webkit-box-align,
                box_align,
                WebkitBoxAlign,
                WEBKIT_PREFIX_PREF)
 CSS_PROP_ALIAS(-webkit-box-pack,
                box_pack,
                WebkitBoxPack,
                WEBKIT_PREFIX_PREF)
 
+// Alias -webkit-flex related properties to their unprefixed equivalents:
+// (Matching ordering at https://drafts.csswg.org/css-flexbox-1/#property-index )
+CSS_PROP_ALIAS(-webkit-flex-direction,
+               flex_direction,
+               WebkitFlexDirection,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex-wrap,
+               flex_wrap,
+               WebkitFlexWrap,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex-flow,
+               flex_flow,
+               WebkitFlexFlow,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-order,
+               order,
+               WebkitOrder,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex,
+               flex,
+               WebkitFlex,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex-grow,
+               flex_grow,
+               WebkitFlexGrow,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex-shrink,
+               flex_shrink,
+               WebkitFlexShrink,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-flex-basis,
+               flex_basis,
+               WebkitFlexBasis,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-justify-content,
+               justify_content,
+               WebkitJustifyContent,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-align-items,
+               align_items,
+               WebkitAlignItems,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-align-self,
+               align_self,
+               WebkitAlignSelf,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-align-content,
+               align_content,
+               WebkitAlignContent,
+               WEBKIT_PREFIX_PREF)
+
 CSS_PROP_ALIAS(-webkit-user-select,
                user_select,
                WebkitUserSelect,
                WEBKIT_PREFIX_PREF)
 
 #ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 CSS_PROP_ALIAS(-webkit-mask,
                mask,

--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -7371,16 +7371,100 @@ if (IsCSSPropertyPrefEnabled("layout.css
   };
   gCSSProperties["-webkit-box-pack"] = {
     domProp: "webkitBoxPack",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
     alias_for: "-moz-box-pack",
     subproperties: [ "-moz-box-pack" ],
   };
+  gCSSProperties["-webkit-flex-direction"] = {
+    domProp: "webkitFlexDirection",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "flex-direction",
+    subproperties: [ "flex-direction" ],
+  };
+  gCSSProperties["-webkit-flex-wrap"] = {
+    domProp: "webkitFlexWrap",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "flex-wrap",
+    subproperties: [ "flex-wrap" ],
+  };
+  gCSSProperties["-webkit-flex-flow"] = {
+    domProp: "webkitFlexFlow",
+    inherited: false,
+    type: CSS_TYPE_TRUE_SHORTHAND,
+    alias_for: "flex-flow",
+    subproperties: [ "flex-direction", "flex-wrap" ],
+  };
+  gCSSProperties["-webkit-order"] = {
+    domProp: "webkitOrder",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "order",
+    subproperties: [ "order" ],
+  };
+  gCSSProperties["-webkit-flex"] = {
+    domProp: "webkitFlex",
+    inherited: false,
+    type: CSS_TYPE_TRUE_SHORTHAND,
+    alias_for: "flex",
+    subproperties: [ "flex-grow", "flex-shrink", "flex-basis" ],
+  };
+  gCSSProperties["-webkit-flex-grow"] = {
+    domProp: "webkitFlexGrow",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "flex-grow",
+    subproperties: [ "flex-grow" ],
+  };
+  gCSSProperties["-webkit-flex-shrink"] = {
+    domProp: "webkitFlexShrink",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "flex-shrink",
+    subproperties: [ "flex-shrink" ],
+  };
+  gCSSProperties["-webkit-flex-basis"] = {
+    domProp: "webkitFlexBasis",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "flex-basis",
+    subproperties: [ "flex-basis" ],
+  };
+  gCSSProperties["-webkit-justify-content"] = {
+    domProp: "webkitJustifyContent",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "justify-content",
+    subproperties: [ "justify-content" ],
+  };
+  gCSSProperties["-webkit-align-items"] = {
+    domProp: "webkitAlignItems",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "align-items",
+    subproperties: [ "align-items" ],
+  };
+  gCSSProperties["-webkit-align-self"] = {
+    domProp: "webkitAlignSelf",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "align-self",
+    subproperties: [ "align-self" ],
+  };
+  gCSSProperties["-webkit-align-content"] = {
+    domProp: "webkitAlignContent",
+    inherited: false,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
+    alias_for: "align-content",
+    subproperties: [ "align-content" ],
+  };
   gCSSProperties["-webkit-user-select"] = {
     domProp: "webkitUserSelect",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
     alias_for: "-moz-user-select",
     subproperties: [ "-moz-user-select" ],
   };