Bug 782441 part 2: Tweak ua.css to make flex container properties inherit to ::-moz-scrolled-content, so that flex containers with "overflow" set will honor those properties. r=bz

layout/style/ua.css

@@ -139,6 +139,12 @@
   -moz-column-width: inherit;
   -moz-column-gap: inherit;
   -moz-column-rule: inherit;
+  /* CSS3 flexbox properties that apply to the flex container: */
+  /* align-content: inherit; FIXME: not yet supported (bug 702508) */
+  align-items: inherit;
+  flex-direction: inherit;
+  /* flex-wrap: inherit; FIXME: not yet supported (bug 702508) */
+  justify-content: inherit;
   /* Do not change these. nsCSSFrameConstructor depends on them to create a good
      frame tree. */
   position: static !important;