Never connect a port to the same frame

chrome/browser/extensions/extension_messages_apitest.cc

Index: chrome/browser/extensions/extension_messages_apitest.cc
diff --git a/chrome/browser/extensions/extension_messages_apitest.cc b/chrome/browser/extensions/extension_messages_apitest.cc
index e6e80c4298a458d3381dcc8b304cfba380d1e2b2..a0ba0cbb5ef9fd9395016802a438454e1b5635b3 100644
--- a/chrome/browser/extensions/extension_messages_apitest.cc
+++ b/chrome/browser/extensions/extension_messages_apitest.cc
@@ -162,6 +162,11 @@ IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MessagingEventURL) {
   ASSERT_TRUE(RunExtensionTest("messaging/event_url")) << message_;
 }
 
+// Tests that messages cannot be received from the same frame.
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MessagingBackgroundOnly) {
+  ASSERT_TRUE(RunExtensionTest("messaging/background_only")) << message_;
+}
+
 // Tests connecting from a panel to its extension.
 class PanelMessagingTest : public ExtensionApiTest {
   void SetUpCommandLine(base::CommandLine* command_line) override {