Allow whitelisted content scripts to be injected in WebViews.

extensions/browser/user_script_loader.cc

Index: extensions/browser/user_script_loader.cc
diff --git a/extensions/browser/user_script_loader.cc b/extensions/browser/user_script_loader.cc
index 7daf95d22fe367431d9002748da60ff7b3245439..be4fa0d8e04031c5a385313eebc69743cafc9021 100644
--- a/extensions/browser/user_script_loader.cc
+++ b/extensions/browser/user_script_loader.cc
@@ -378,9 +378,9 @@ void UserScriptLoader::OnScriptsLoaded(
 void UserScriptLoader::SendUpdate(content::RenderProcessHost* process,
                                   base::SharedMemory* shared_memory,
                                   const std::set<HostID>& changed_hosts) {
-  // Don't allow injection of extensions' content scripts into <webview>.
-  if (process->IsIsolatedGuest() && host_id().id().empty())
-    return;
+  // Don't allow injection of non-whitelisted extensions' content scripts
+  // into <webview>.
+  bool whitelisted_only = process->IsIsolatedGuest() && host_id().id().empty();
 
   // Make sure we only send user scripts to processes in our browser_context.
   if (!ExtensionsBrowserClient::Get()->IsSameContext(
@@ -399,7 +399,9 @@ void UserScriptLoader::SendUpdate(content::RenderProcessHost* process,
 
   if (base::SharedMemory::IsHandleValid(handle_for_process)) {
     process->Send(new ExtensionMsg_UpdateUserScripts(handle_for_process,
-                                                     host_id(), changed_hosts));
+                                                     host_id(),
+                                                     changed_hosts,
+                                                     whitelisted_only));
   }
 }