Use JS to clear field, should be more performant

lib/capybara/selenium/node.rb

@@ -32,8 +32,8 @@ class Capybara::Selenium::Node < Capybara::Driver::Node
       path_names = value.to_s.empty? ? [] : value
       native.send_keys(*path_names)
     elsif tag_name == 'textarea' or tag_name == 'input'
-      chars = native[:value].size
-      native.send_keys(([:right] * chars) + ([:backspace] * chars) + [ value.to_s ])
+      driver.browser.execute_script "arguments[0].value = ''", native
+      native.send_keys(value.to_s)
     end
   end