system testing: disable chrome's search engine choice modal

starting chrome with a fresh profile shows a search engine choice screen
which will break any tests. passing a special argument will disable the
screen.

see SeleniumHQ/selenium#14431

also:
- refactor default chrome option initialization
- compress browser option initialization

actionpack/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   System Testing: Disable Chrome's search engine choice by default in system tests.
+
+    *glaszig*
+
 *   Fix `Request#raw_post` raising `NoMethodError` when `rack.input` is `nil`.
 
     *Hartley McGuire*

actionpack/lib/action_dispatch/system_testing/browser.rb

@@ -9,7 +9,6 @@ class Browser # :nodoc:
 
       def initialize(name)
         @name = name
-        set_default_options
       end
 
       def type
@@ -27,9 +26,9 @@ def options
         @options ||=
           case type
           when :chrome
-            ::Selenium::WebDriver::Chrome::Options.new
+            default_chrome_options
           when :firefox
-            ::Selenium::WebDriver::Firefox::Options.new
+            default_firefox_options
           end
       end
 
@@ -49,26 +48,18 @@ def preload
       end
 
       private
-        def set_default_options
-          case name
-          when :headless_chrome
-            set_headless_chrome_browser_options
-          when :headless_firefox
-            set_headless_firefox_browser_options
-          end
+        def default_chrome_options
+          options = ::Selenium::WebDriver::Chrome::Options.new
+          options.add_argument("--disable-search-engine-choice-screen")
+          options.add_argument("--headless") if name == :headless_chrome
+          options.add_argument("--disable-gpu") if Gem.win_platform?
+          options
         end
 
-        def set_headless_chrome_browser_options
-          configure do |capabilities|
-            capabilities.add_argument("--headless")
-            capabilities.add_argument("--disable-gpu") if Gem.win_platform?
-          end
-        end
-
-        def set_headless_firefox_browser_options
-          configure do |capabilities|
-            capabilities.add_argument("-headless")
-          end
+        def default_firefox_options
+          options = ::Selenium::WebDriver::Firefox::Options.new
+          options.add_argument("-headless") if name == :headless_firefox
+          options
         end
 
         def resolve_driver_path(namespace)

actionpack/test/dispatch/system_testing/driver_test.rb

@@ -82,7 +82,7 @@ class DriverTest < ActiveSupport::TestCase
 
     expected = {
       "goog:chromeOptions" => {
-        "args" => ["start-maximized"],
+        "args" => ["--disable-search-engine-choice-screen", "start-maximized"],
         "mobileEmulation" => { "deviceName" => "iphone 6" },
         "prefs" => { "detach" => true }
       },
@@ -101,7 +101,7 @@ class DriverTest < ActiveSupport::TestCase
 
     expected = {
       "goog:chromeOptions" => {
-        "args" => ["--headless", "start-maximized"],
+        "args" => ["--disable-search-engine-choice-screen", "--headless", "start-maximized"],
         "mobileEmulation" => { "deviceName" => "iphone 6" },
         "prefs" => { "detach" => true }
       },