Bug 1342315 - Add reftests to check that we disable ligatures when letter-spacing is in effect. r=jrmuizel

layout/reftests/text/letter-spacing-nolig-1-ref.html

@@ -0,0 +1,13 @@
+<style>
+.a {
+  font: 32px/2 Times;
+}
+.b {
+  font: 32px/2 Times;
+  letter-spacing: 1em;
+}
+</style>
+
+<div class="a">office
+
+<div class="b">off&zwnj;ice

layout/reftests/text/letter-spacing-nolig-1.html

@@ -0,0 +1,13 @@
+<style>
+.a {
+  font: 32px/2 Times;
+}
+.b {
+  font: 32px/2 Times;
+  letter-spacing: 1em;
+}
+</style>
+
+<div class="a">office
+
+<div class="b">office

layout/reftests/text/letter-spacing-nolig-2-ref.html

@@ -0,0 +1,17 @@
+<style>
+@font-face {
+  font-family: libertine;
+  src: url(../fonts/LinLibertine_Re-4.7.5.woff);
+}
+.a {
+  font: 32px/2 libertine;
+}
+.b {
+  font: 32px/2 libertine;
+  letter-spacing: 1em;
+}
+</style>
+
+<div class="a">office
+
+<div class="b">of&zwnj;f&zwnj;ice

layout/reftests/text/letter-spacing-nolig-2.html

@@ -0,0 +1,17 @@
+<style>
+@font-face {
+  font-family: libertine;
+  src: url(../fonts/LinLibertine_Re-4.7.5.woff);
+}
+.a {
+  font: 32px/2 libertine;
+}
+.b {
+  font: 32px/2 libertine;
+  letter-spacing: 1em;
+}
+</style>
+
+<div class="a">office
+
+<div class="b">office

layout/reftests/text/reftest.list

@@ -346,3 +346,6 @@ HTTP(..) == space-font-1.html space-font-1-ref.html
 # color glyphs, opacity, and RTL runs - bug 1318539
 == color-opacity-rtl-1.html color-opacity-rtl-1-ref.html
 == color-opacity-rtl-2.html color-opacity-rtl-2-ref.html
+
+== letter-spacing-nolig-1.html letter-spacing-nolig-1-ref.html
+HTTP(..) == letter-spacing-nolig-2.html letter-spacing-nolig-2.html