Convert FaviconDownloader to use the new navigation callbacks.

chrome/browser/extensions/favicon_downloader.h

Index: chrome/browser/extensions/favicon_downloader.h
diff --git a/chrome/browser/extensions/favicon_downloader.h b/chrome/browser/extensions/favicon_downloader.h
index 77cf859695718f37614e35fa7cec2151d9bc8956..09b96d61e2efb81466cea577fa5446f33b59b718 100644
--- a/chrome/browser/extensions/favicon_downloader.h
+++ b/chrome/browser/extensions/favicon_downloader.h
@@ -71,9 +71,8 @@ class FaviconDownloader : public content::WebContentsObserver {
                           const std::vector<gfx::Size>& original_bitmap_sizes);
 
   // content::WebContentsObserver overrides:
-  void DidNavigateMainFrame(
-      const content::LoadCommittedDetails& details,
-      const content::FrameNavigateParams& params) override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
   void DidUpdateFaviconURL(
       const std::vector<content::FaviconURL>& candidates) override;