Add more chrome flags

Found in ref: teamcapybara/capybara#2796

Author: tvdeyen

lib/solidus_dev_support/rspec/capybara.rb

@@ -7,6 +7,7 @@
 
 # Set Chrome version you want to use
 CAPYBARA_JAVASCRIPT_DRIVER_VERSION = ENV.fetch('CAPYBARA_JAVASCRIPT_DRIVER_VERSION', "135")
+# Make sure Selenium downloads this version of Chrome
 ENV['SE_BROWSER_VERSION'] = CAPYBARA_JAVASCRIPT_DRIVER_VERSION
 
 Capybara.javascript_driver = ENV.fetch('CAPYBARA_JAVASCRIPT_DRIVER', "solidus_chrome_headless").to_sym
@@ -20,7 +21,20 @@
     opts.add_argument("--no-sandbox")
     opts.add_argument("--window-size=#{CAPYBARA_WINDOW_SIZE}")
     opts.add_argument("--disable-search-engine-choice-screen")
-    opts.add_argument("--disable-backgrounding-occluded-windows")
+
+    # From https://github.com/teamcapybara/capybara/issues/2796
+    # Chrome flags found from:
+    # - https://peter.sh/experiments/chromium-command-line-switches/
+    # - https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
+    #
+    # Disable timers being throttled in background pages/tabs. Useful for parallel test runs.
+    opts.add_argument("disable-background-timer-throttling")
+    # Normally, Chrome will treat a "foreground" tab instead as backgrounded if the surrounding window is occluded (aka
+    # visually covered) by another window. This flag disables that. Useful for parallel test runs.
+    opts.add_argument("disable-backgrounding-occluded-windows")
+    # This disables non-foreground tabs from getting a lower process priority. Useful for parallel test runs.
+    opts.add_argument("disable-renderer-backgrounding")
+
     opts.browser_version = CAPYBARA_JAVASCRIPT_DRIVER_VERSION
   end
   Capybara::Selenium::Driver.new(app, browser: :chrome, options: browser_options)