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

chrome/renderer/chrome_render_frame_observer.h

Index: chrome/renderer/chrome_render_frame_observer.h
diff --git a/chrome/renderer/chrome_render_frame_observer.h b/chrome/renderer/chrome_render_frame_observer.h
index 5db7d4a311b6bcd5f8c6049319396d215cfd61c2..83cce6a06428b78d4fbdd98b91bf88655ab523f9 100644
--- a/chrome/renderer/chrome_render_frame_observer.h
+++ b/chrome/renderer/chrome_render_frame_observer.h
@@ -31,6 +31,7 @@ class ChromeRenderFrameObserver : public content::RenderFrameObserver {
       const gfx::Size& thumbnail_max_size_pixels);
   void OnPrintNodeUnderContextMenu();
   void OnAppBannerPromptRequest(int request_id, const std::string& platform);
+  void OnAppBannerDebugMessageRequest(const std::string& message);
 
   DISALLOW_COPY_AND_ASSIGN(ChromeRenderFrameObserver);
 };