Stop injecting null chrome binaries

Author: barancev

java/server/src/org/openqa/grid/selenium/node/ChromeMutator.java

@@ -57,7 +57,7 @@ public ImmutableCapabilities apply(ImmutableCapabilities capabilities) {
       options.putAll(asMap);
     }
 
-    if (!(options.get("binary") instanceof String)) {
+    if (options.get("binary") == null && config.getCapability("chrome_binary") != null) {
       options.put("binary", config.getCapability("chrome_binary"));
     }
 

java/server/test/org/openqa/grid/selenium/node/ChromeMutatorTest.java

@@ -18,6 +18,7 @@
 package org.openqa.grid.selenium.node;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
 import static org.openqa.selenium.chrome.ChromeOptions.CAPABILITY;
 
@@ -70,6 +71,18 @@ public void shouldInjectBinaryIfNotSpecified() {
         defaultConfig.getCapability("chrome_binary"));
   }
 
+  @Test
+  public void shouldNotInjectNullBinary() {
+    ImmutableCapabilities caps = new ImmutableCapabilities(new ChromeOptions());
+    ImmutableCapabilities seen = new ChromeMutator(
+        new ImmutableCapabilities("browserName", "chrome")).apply(caps);
+
+    @SuppressWarnings("unchecked")
+    Map<String, Object> options = (Map<String, Object>) seen.getCapability(CAPABILITY);
+
+    assertFalse(options.containsKey("binary"));
+  }
+
   @Test
   public void shouldNotInjectBinaryIfSpecified() {
     ImmutableCapabilities caps = new ImmutableCapabilities(new ChromeOptions().setBinary("cheese"));