nodejs: enable use of firefox profiles for marionette (#2406)

Author: andreastt

javascript/node/selenium-webdriver/firefox/index.js

@@ -354,6 +354,12 @@ class Driver extends webdriver.WebDriver {
       binary = new Binary(binary);
     }
 
+    let profile = new Profile();
+    if (caps.has(Capability.PROFILE)) {
+      profile = caps.get(Capability.PROFILE);
+      caps.delete(Capability.PROFILE);
+    }
+
     let serverUrl, onQuit;
 
     // Users must now explicitly disable marionette to use the legacy
@@ -367,14 +373,9 @@ class Driver extends webdriver.WebDriver {
       let service = createGeckoDriverService(binary);
       serverUrl = service.start();
       onQuit = () => service.kill();
+      caps.set(Capability.PROFILE, profile.encode());
 
     } else {
-      let profile = new Profile;
-      if (caps.has(Capability.PROFILE)) {
-        profile = caps.get(Capability.PROFILE);
-        caps.delete(Capability.PROFILE);
-      }
-
       let freePort = portprober.findFreePort();
       let preparedProfile =
           freePort.then(port => prepareProfile(profile, port));

javascript/node/selenium-webdriver/firefox/profile.js

@@ -188,8 +188,8 @@ function decode(data) {
 
 /**
  * Models a Firefox profile directory for use with the FirefoxDriver. The
- * {@code Profile} directory uses an in-memory model until {@link #writeToDisk}
- * is called.
+ * {@code Profile} directory uses an in-memory model until
+ * {@link #writeToDisk} or {@link #encode} is called.
  */
 class Profile {
   /**
@@ -366,8 +366,12 @@ class Profile {
   }
 
   /**
-   * Encodes this profile as a zipped, base64 encoded directory.
-   * @return {!Promise<string>} A promise for the encoded profile.
+   * Write profile to disk, compress its containing directory, and return
+   * it as a Base64 encoded string.
+   *
+   * @return {!Promise<string>} A promise for the encoded profile as
+   *     Base64 string.
+   *
    */
   encode() {
     return this.writeToDisk(true).then(function(dir) {