Allow multiple logging::LogMessage{Handler,Listener}s

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index ef14c8360cf0d7bea2c163f1ed6a9a5496d96fa9..d5f96ae8c67682df9f1abb89d81e507a86c9e1e2 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -981,6 +981,10 @@ void RenderFrameHostImpl::OnDidAddMessageToConsole(
   if (delegate_->DidAddMessageToConsole(level, message, line_no, source_id))
     return;
 
+  // In order for CSP violation detections in the tests to work, console
+  // messages must be forwarded to logging::LogMessage().
+  // Ref: https://crbug.com/638050
+
   // Pass through log level only on WebUI pages to limit console spew.
   const bool is_web_ui =
       HasWebUIScheme(delegate_->GetMainFrameLastCommittedURL());