Revert of MD Downloads: track downloads in C++, dispatch discrete JS updates

chrome/browser/ui/webui/md_downloads/md_downloads_ui.h

Index: chrome/browser/ui/webui/md_downloads/md_downloads_ui.h
diff --git a/chrome/browser/ui/webui/md_downloads/md_downloads_ui.h b/chrome/browser/ui/webui/md_downloads/md_downloads_ui.h
index 55d21e1dedcedc8cf5c7c831fef367f179ea962c..37ce107a7b30abfdb1058325231e722311e977ce 100644
--- a/chrome/browser/ui/webui/md_downloads/md_downloads_ui.h
+++ b/chrome/browser/ui/webui/md_downloads/md_downloads_ui.h
@@ -13,12 +13,6 @@
 class RefCountedMemory;
 }
 
-namespace content {
-class RenderViewHost;
-}
-
-class MdDownloadsDOMHandler;
-
 class MdDownloadsUI : public content::WebUIController {
  public:
   explicit MdDownloadsUI(content::WebUI* web_ui);
@@ -26,12 +20,7 @@
   static base::RefCountedMemory* GetFaviconResourceBytes(
       ui::ScaleFactor scale_factor);
 
-  // content::WebUIController:
-  void RenderViewReused(content::RenderViewHost* render_view_host) override;
-
  private:
-  MdDownloadsDOMHandler* handler_;  // Weak.
-
   DISALLOW_COPY_AND_ASSIGN(MdDownloadsUI);
 };