Remove ChromeBrowserProvider::GetFaviconForURL().

ios/chrome/browser/downstream_chromium_browser_provider.h

Index: ios/chrome/browser/downstream_chromium_browser_provider.h
diff --git a/ios/chrome/browser/downstream_chromium_browser_provider.h b/ios/chrome/browser/downstream_chromium_browser_provider.h
index 2e1e189cbbd42aad20b8d25e244bc23f134d2847..94132199f192b12017f8eced6c474bd858eb9ba6 100644
--- a/ios/chrome/browser/downstream_chromium_browser_provider.h
+++ b/ios/chrome/browser/downstream_chromium_browser_provider.h
@@ -19,11 +19,6 @@ class DownstreamChromiumBrowserProvider : public ChromiumBrowserProvider {
   // ChromeBrowserProvider implementations.  All of these will move upstream
   // into ChromiumBrowserProvider eventually, and from there callers will be
   // converted to not go through the provider API at all.
-  void GetFaviconForURL(
-      ios::ChromeBrowserState* browser_state,
-      const GURL& page_url,
-      const std::vector<int>& desired_sizes_in_pixel,
-      const favicon_base::FaviconResultsCallback& callback) const override;
   std::unique_ptr<sync_sessions::SyncedWindowDelegatesGetter>
   CreateSyncedWindowDelegatesGetter(
       ios::ChromeBrowserState* browser_state) override;