Look for chromedriver on the system PATH too

Squashed commit of the following:

commit cf1c1ec
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Tue Jan 13 16:56:33 2015 +1000

    Add suggestions from djansen

commit be3e8a4
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Fri Dec 19 15:13:58 2014 +1000

    Look for chromedriver on the system PATH too

functional-test/src/main/java/org/zanata/page/WebDriverFactory.java

@@ -29,6 +29,7 @@
 import org.openqa.selenium.firefox.FirefoxBinary;
 import org.openqa.selenium.firefox.FirefoxDriver;
 import org.openqa.selenium.firefox.FirefoxProfile;
+import org.openqa.selenium.os.CommandLine;
 import org.openqa.selenium.remote.Augmenter;
 import org.openqa.selenium.remote.DesiredCapabilities;
 import org.openqa.selenium.remote.RemoteWebDriver;
@@ -107,11 +108,19 @@ private WebDriver createPlainDriver() {
     }
 
     private WebDriver configureChromeDriver() {
+        // TODO can we use this? it will use less code, but it will use DISPLAY rather than webdriver.display
+//        System.setProperty(ChromeDriverService.CHROME_DRIVER_EXE_PROPERTY,
+//                getChromeDriver().getAbsolutePath()));
+//        System.setProperty(ChromeDriverService.CHROME_DRIVER_LOG_PROPERTY,
+//                PropertiesHolder.getProperty("webdriver.log"));
+//        driverService = ChromeDriverService.createDefaultService();
+
+        @SuppressWarnings("deprecation")
+        File chromeDriver = getChromeDriver();
         driverService =
                 new ChromeDriverService.Builder()
                         .usingDriverExecutable(
-                                new File(PropertiesHolder.properties
-                                        .getProperty("webdriver.chrome.driver")))
+                                chromeDriver)
                         .usingAnyFreePort()
                         .withEnvironment(
                                 ImmutableMap
@@ -121,6 +130,7 @@ private WebDriver configureChromeDriver() {
                         .withLogFile(
                                 new File(PropertiesHolder.properties
                                         .getProperty("webdriver.log"))).build();
+
         DesiredCapabilities capabilities = DesiredCapabilities.chrome();
         capabilities
                 .setCapability("chrome.binary", PropertiesHolder.properties
@@ -136,6 +146,32 @@ private WebDriver configureChromeDriver() {
                                 capabilities)));
     }
 
+    /**
+     * Returns a File pointing to a chromedriver binary, searching the PATH
+     * if necessary. If the property 'webdriver.chrome.driver' points to an
+     * executable, uses that.  Otherwise, searches PATH for the specified
+     * executable.  Searches for 'chromedriver' if the property is null or
+     * empty.
+     * @return a File pointing to the executable
+     * @deprecated use ChromeDriverService.createDefaultService() if you can
+     */
+    @Deprecated
+    private File getChromeDriver() {
+        String exeName = PropertiesHolder.getProperty("webdriver.chrome.driver");
+        if (exeName == null || exeName.isEmpty()) {
+            exeName = CommandLine.find("chromedriver");
+        } else if (!new File(exeName).canExecute()) {
+            exeName = CommandLine.find(exeName);
+        }
+        if (exeName == null) {
+            throw new RuntimeException("Please ensure chromedriver is on " +
+                    "your system PATH or specified by the property " +
+                    "'webdriver.chrome.driver'.  Get it here: " +
+                    "http://chromedriver.storage.googleapis.com/index.html");
+        }
+        return new File(exeName);
+    }
+
     private WebDriver configureFirefoxDriver() {
         final String pathToFirefox =
                 Strings.emptyToNull(PropertiesHolder.properties