Revert of PlzNavigate: Enforce 'frame-src' CSP on the browser.

content/browser/frame_host/navigation_entry_impl.cc

Index: content/browser/frame_host/navigation_entry_impl.cc
diff --git a/content/browser/frame_host/navigation_entry_impl.cc b/content/browser/frame_host/navigation_entry_impl.cc
index 4c3ffa735563d0cbbac8da990de95fc6506e4672..c7f361d414faaa465a92845739917c93414da36d 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -686,8 +686,7 @@
       !IsViewSourceMode(), should_replace_entry(), ui_timestamp, report_type,
       GetBaseURLForDataURL(), GetHistoryURLForDataURL(), previews_state,
       navigation_start, method, post_body ? post_body : post_data_,
-      base::Optional<SourceLocation>(),
-      CSPDisposition::CHECK /* should_check_main_world_csp */);
+      base::Optional<SourceLocation>());
 }
 
 StartNavigationParams NavigationEntryImpl::ConstructStartNavigationParams()