Fix up the FirefoxDriverTests

Delete tests that don't apply any more, and fix up
those that are meant to be used.

Author: shs96c

java/client/src/org/openqa/selenium/firefox/FirefoxBinary.java

@@ -175,6 +175,10 @@ public void addCommandLineOptions(String... options) {
     extraOptions.addAll(Lists.newArrayList(options));
   }
 
+  void amendOptions(FirefoxOptions options) {
+    options.addArguments(extraOptions);
+  }
+
   protected boolean isOnLinux() {
     return Platform.getCurrent().is(Platform.LINUX);
   }

java/client/src/org/openqa/selenium/firefox/FirefoxOptions.java

@@ -158,6 +158,7 @@ public boolean isLegacy() {
 
   public FirefoxOptions setBinary(FirefoxBinary binary) {
     this.actualBinary = Preconditions.checkNotNull(binary);
+    binary.amendOptions(this);
     this.binaryPath = null;
     return this;
   }
@@ -319,6 +320,10 @@ public FirefoxOptions setLogLevel(Level logLevel) {
   }
 
   public FirefoxOptions addDesiredCapabilities(Capabilities desiredCapabilities) {
+    if (desiredCapabilities == null) {
+      return this;
+    }
+
     this.desiredCapabilities.merge(desiredCapabilities);
 
     FirefoxProfile suggestedProfile = extractProfile(desiredCapabilities);
@@ -335,6 +340,7 @@ public FirefoxOptions addDesiredCapabilities(Capabilities desiredCapabilities) {
       }
       profile = suggestedProfile;
     }
+
     Object binary = desiredCapabilities.getCapability(BINARY);
     if (binary != null) {
       if (binary instanceof File) {