Don't route a non-frame widget's keyboard event to main frame widget.

content/public/test/browser_test_utils.cc

Index: content/public/test/browser_test_utils.cc
diff --git a/content/public/test/browser_test_utils.cc b/content/public/test/browser_test_utils.cc
index 27083866f81ff1442bda724f05c1ab1c098b3803..79fd6170245e383d4f99aa70ed7ff58aec365016 100644
--- a/content/public/test/browser_test_utils.cc
+++ b/content/public/test/browser_test_utils.cc
@@ -227,8 +227,11 @@ void InjectRawKeyEvent(WebContents* web_contents,
                        int modifiers) {
   NativeWebKeyboardEvent event;
   BuildSimpleWebKeyEvent(type, key_code, native_key_code, modifiers, &event);
-  static_cast<WebContentsImpl*>(web_contents)
-      ->GetFocusedRenderWidgetHost()
+  WebContentsImpl* web_contents_impl =
+      static_cast<WebContentsImpl*>(web_contents);
+  RenderWidgetHostImpl* main_frame_rwh =
+      web_contents_impl->GetMainFrame()->GetRenderWidgetHost();
+  web_contents_impl->GetFocusedRenderWidgetHost(main_frame_rwh)
       ->ForwardKeyboardEvent(event);
 }