Try run for https://codereview.chromium.org/426593007.

extensions/renderer/dispatcher.cc

Index: extensions/renderer/dispatcher.cc
diff --git a/extensions/renderer/dispatcher.cc b/extensions/renderer/dispatcher.cc
index f27eba89d7aa253ff021d15e56cd78abeec0cd75..e2a481283fb17c51cef351cef8f7b3d5b2391a2f 100644
--- a/extensions/renderer/dispatcher.cc
+++ b/extensions/renderer/dispatcher.cc
@@ -1171,6 +1171,9 @@ Feature::Context Dispatcher::ClassifyJavaScriptContext(
     int extension_group,
     const GURL& url,
     const blink::WebSecurityOrigin& origin) {
+  // WARNING: This logic must match ProcessMap::GuessContextType, as much as
+  // possible.
+
   DCHECK_GE(extension_group, 0);
   if (extension_group == EXTENSION_GROUP_CONTENT_SCRIPTS) {
     return extension ?  // TODO(kalman): when does this happen?