Use IOSImageDataFetcherWrapper for favicon

components/image_fetcher/image_data_fetcher.cc

Index: components/image_fetcher/image_data_fetcher.cc
diff --git a/components/image_fetcher/image_data_fetcher.cc b/components/image_fetcher/image_data_fetcher.cc
index a2916c65e1b839af8f4ee001b6c348b43c20f14c..204fa95d7e80df557d859271fbe6674c3df7b2bc 100644
--- a/components/image_fetcher/image_data_fetcher.cc
+++ b/components/image_fetcher/image_data_fetcher.cc
@@ -82,9 +82,11 @@ void ImageDataFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
   bool success = source->GetStatus().status() == net::URLRequestStatus::SUCCESS;
 
   RequestMetadata metadata;
+  metadata.response_code = RESPONSE_CODE_INVALID;
   if (success && source->GetResponseHeaders()) {
     source->GetResponseHeaders()->GetMimeType(&metadata.mime_type);
-    success &= (source->GetResponseHeaders()->response_code() == net::HTTP_OK);
+    metadata.response_code = source->GetResponseHeaders()->response_code();
+    success &= (metadata.response_code == net::HTTP_OK);
   }
 
   std::string image_data;