Log messages regarding why app banners aren't displayed to the console

chrome/renderer/chrome_render_frame_observer.cc

Index: chrome/renderer/chrome_render_frame_observer.cc
diff --git a/chrome/renderer/chrome_render_frame_observer.cc b/chrome/renderer/chrome_render_frame_observer.cc
index bf53999771bcc97a6eeb30227c98598b73067380..1518bf604b59d9a4e5b0b6057a44e16923ecb914 100644
--- a/chrome/renderer/chrome_render_frame_observer.cc
+++ b/chrome/renderer/chrome_render_frame_observer.cc
@@ -100,6 +100,8 @@ bool ChromeRenderFrameObserver::OnMessageReceived(const IPC::Message& message) {
                         OnPrintNodeUnderContextMenu)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_AppBannerPromptRequest,
                         OnAppBannerPromptRequest)
+    IPC_MESSAGE_HANDLER(ChromeViewMsg_AppBannerDebugMessageRequest,
+                        OnAppBannerDebugMessageRequest)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -208,3 +210,9 @@ void ChromeRenderFrameObserver::OnAppBannerPromptRequest(
   Send(new ChromeViewHostMsg_AppBannerPromptReply(
       routing_id(), request_id, reply));
 }
+
+void ChromeRenderFrameObserver::OnAppBannerDebugMessageRequest(
+    const std::string& message) {
+  render_frame()->GetWebFrame()->addMessageToConsole(blink::WebConsoleMessage(
+      blink::WebConsoleMessage::LevelDebug, base::UTF8ToUTF16(message)));
+}