Use native implementation of dangerous download infobar

chrome/browser/android/download/download_controller_base.h

Index: chrome/browser/android/download/download_controller_base.h
diff --git a/chrome/browser/android/download/download_controller_base.h b/chrome/browser/android/download/download_controller_base.h
index ec850984e53efacbfb9ff851cabcb03ba89f5618..6a9bf6941db8677b6adae9cf54fe7df3b4c36047 100644
--- a/chrome/browser/android/download/download_controller_base.h
+++ b/chrome/browser/android/download/download_controller_base.h
@@ -70,11 +70,6 @@ class DownloadControllerBase : public content::DownloadItem::Observer {
       content::WebContents* web_contents,
       bool is_link, const std::string& extra_headers) = 0;
 
-  // Called when a dangerous download item is verified or rejected.
-  virtual void DangerousDownloadValidated(content::WebContents* web_contents,
-                                          const std::string& download_guid,
-                                          bool accept) = 0;
-
   // Callback when user permission prompt finishes. Args: whether file access
   // permission is acquired.
   typedef base::Callback<void(bool)> AcquireFileAccessPermissionCallback;