Bug 1364011 - Port bug 1363033 to TB [Increase length of tab label fade]. r=jorgk

mail/base/content/tabmail.css

@@ -35,11 +35,11 @@
 }
 
 .tab-label-container[textoverflow] {
-  mask-image: linear-gradient(to left, transparent, black 1em);
+  mask-image: linear-gradient(to left, transparent, black 2em);
 }
 
 .tab-label-container[textoverflow]:-moz-locale-dir(rtl) {
-  mask-image: linear-gradient(to right, transparent, black 1em);
+  mask-image: linear-gradient(to right, transparent, black 2em);
 }
 
 .tab-label {

mail/themes/shared/mail/tabmail.css

@@ -85,7 +85,7 @@
 }
 
 .tab-content > .tab-close-button {
-  margin-inline-start: 2px;
+  margin-inline-start: 1px;
   margin-inline-end: -2px;
   padding: 0;
 }