Disable /dev/shm in CI

According to the Chrome source code (https://chromium.googlesource.com/chromium/src/base/+/master/base_switches.cc#120):

The /dev/shm partition is too small in certain VM environments, causing Chrome
to fail or crash (see http://crbug.com/715363). Use this flag to work-around
this issue (a temporary directory will always be used to create anonymous
shared memory files).

Addresses gitlab-org/gitlab-ee#4252 but doesn't appear to cure it completely.

features/support/capybara.rb

@@ -29,6 +29,9 @@ Capybara.register_driver :chrome do |app|
     options.add_argument("disable-gpu")
   end
 
+  # Disable /dev/shm use in CI. See https://gitlab.com/gitlab-org/gitlab-ee/issues/4252
+  options.add_argument("disable-dev-shm-usage") if ENV['CI'] || ENV['CI_SERVER']
+
   Capybara::Selenium::Driver.new(
     app,
     browser: :chrome,

spec/support/capybara.rb

@@ -33,6 +33,9 @@ Capybara.register_driver :chrome do |app|
     options.add_argument("disable-gpu")
   end
 
+  # Disable /dev/shm use in CI. See https://gitlab.com/gitlab-org/gitlab-ee/issues/4252
+  options.add_argument("disable-dev-shm-usage") if ENV['CI'] || ENV['CI_SERVER']
+
   Capybara::Selenium::Driver.new(
     app,
     browser: :chrome,