Prevent initial display of modal dialogs when loading.

BUG=None
TEST=Manual


Review URL: http://codereview.chromium.org/9611002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@125101 0039d316-1c4b-4281-b951-d872f2087c98

remoting/webapp/main.css

@@ -476,4 +476,12 @@ button {
 
 * {
   box-sizing: border-box;
-}
+}
+
+/*
+ * Setting hidden on elements that match some rule overriding 'display' doesn't
+ * do what you would expect unless this is made explicit (and !important).
+ */
+[hidden] {
+  display: none !important;
+}