Bug 1386964 - Set default tab height and mark flaky viewport-units-css2-001.html subtests as passing on Linux. r=dholbert

MozReview-Commit-ID: 5gLgepyDiaW

--HG--
extra : rebase_source : dacd6ced6843e8c819733b05a95eafab853873a9

browser/themes/shared/tabs.inc.css

@@ -6,12 +6,10 @@
 
 :root {
   --tab-toolbar-navbar-overlap: 1px;
-/* Temporarily using the compact tab strip by default because of bug 1386964:
   --tab-min-height: 33px;
 }
 
 :root[uidensity=compact] {
-*/
   --tab-min-height: 29px;
 }
 

testing/web-platform/meta/css/css-values-3/viewport-units-css2-001.html.ini

@@ -7,10 +7,12 @@
       if not debug and e10s and (os == "win") and (version == "6.2.9200") and (processor == "x86_64") and (bits == 64): FAIL
 
   [vh length applied to border-top-width]
-    expected: FAIL
+    expected:
+      if os != "linux": FAIL
 
   [vmin length applied to border-top-width]
-    expected: FAIL
+    expected:
+      if os != "linux": FAIL
 
   [vmax length applied to border-top-width]
     expected: