Rename function to avoid name conflict

Author: davepagurek

tasks/test/mocha-chrome.js

@@ -43,7 +43,7 @@ module.exports = function(grunt) {
               'base64'
             );
           });
-          await page.exposeFunction('writeFile', function(filename, data) {
+          await page.exposeFunction('writeTextFile', function(filename, data) {
             fs.mkdirSync('test/' + path.dirname(filename), { recursive: true });
             fs.writeFileSync(
               'test/' + filename,

test/unit/visual/visualTest.js

@@ -157,7 +157,7 @@ window.visualTest = function(
         );
       }
       if (!expectedScreenshots) {
-        writeFile(
+        writeTextFile(
           `unit/visual/screenshots/${name}/metadata.json`,
           JSON.stringify({ numScreenshots: actual.length }, null, 2)
         );