XFA - Fix xfaLink class to make links work (bug 1735738)

There were some links not working in some XFA files,I realized that the anchor tag that contains the link has an inline display and couldn't receive any height, solved this by adding a "position: absolute". Tested with two different files in Firefox Nightly and Chrome and now all links are working perfectly fine. Added reftest to avoid future regressions

Author: Catherine

test/driver.js

@@ -291,6 +291,10 @@ var rasterizeXfaLayer = (function rasterizeXfaLayerClosure() {
       file: "../web/xfa_layer_builder.css",
       promise: null,
     },
+    overrides: {
+      file: "./xfa_layer_builder_overrides.css",
+      promise: null,
+    },
   };
 
   function getXfaLayerStyle() {
@@ -326,8 +330,8 @@ var rasterizeXfaLayer = (function rasterizeXfaLayerClosure() {
       foreignObject.appendChild(div);
 
       stylePromise
-        .then(async ([cssRules]) => {
-          style.textContent = fontRules + "\n" + cssRules;
+        .then(async ([common, overrides]) => {
+          style.textContent = common + "\n" + overrides;
 
           XfaLayer.render({
             xfa,

test/pdfs/.gitignore

@@ -380,6 +380,7 @@
 !issue2128r.pdf
 !issue5540.pdf
 !issue5549.pdf
+!xfa_bug1735738.pdf.link
 !visibility_expressions.pdf
 !issue5475.pdf
 !issue10519_reduced.pdf

test/pdfs/xfa_bug1735738.pdf

@@ -0,0 +1 @@
+https://bugzilla.mozilla.org/attachment.cgi?id=9227382