Move CookieSettings to //components/content_settings/core/browser.

This CL splits the factory in a separate file and moves the service in
the component.
The class is also moved to the content_settings namespace.

BUG=503973
TBR=jochen

Review URL: https://codereview.chromium.org/1214763002

Cr-Commit-Position: refs/heads/master@{#336745}
diff --git a/components/content_settings.gypi b/components/content_settings.gypi
index 984b4541..5fcbe00 100644
--- a/components/content_settings.gypi
+++ b/components/content_settings.gypi
@@ -50,6 +50,8 @@
         'content_settings/core/browser/content_settings_usages_state.h',
         'content_settings/core/browser/content_settings_utils.cc',
         'content_settings/core/browser/content_settings_utils.h',
+        'content_settings/core/browser/cookie_settings.cc',
+        'content_settings/core/browser/cookie_settings.h',
         'content_settings/core/browser/host_content_settings_map.cc',
         'content_settings/core/browser/host_content_settings_map.h',
         'content_settings/core/browser/local_shared_objects_counter.h',