Protobuf for Traffic Annotation and first use by a URLFetcher.

chrome/browser/net/file_downloader.cc

Index: chrome/browser/net/file_downloader.cc
diff --git a/chrome/browser/net/file_downloader.cc b/chrome/browser/net/file_downloader.cc
index aa57047b7c2f62bbe5d959df52aacae95f794c74..7864aa9c1f8c459f17c3485f5a754dc0ab34509b 100644
--- a/chrome/browser/net/file_downloader.cc
+++ b/chrome/browser/net/file_downloader.cc
@@ -25,9 +25,33 @@ FileDownloader::FileDownloader(const GURL& url,
                                net::URLRequestContextGetter* request_context,
                                const DownloadFinishedCallback& callback)
     : callback_(callback),
-      fetcher_(URLFetcher::Create(url, URLFetcher::GET, this)),
       local_path_(path),
       weak_ptr_factory_(this) {
+  net::NetworkTrafficAnnotationTag traffic_annotation =

[battre, 2017/02/01 16:25:58]

FileDownloader should take a net::NetworkTrafficAnnotationTag as a parameter
because it can be used as a network abstraction by different components. I
suggest to remove it from this CL.

[Ramin Halavati, 2017/02/02 07:44:24]

Done.

+      net::DefineNetworkTrafficAnnotation("", R"(
+        semantics {
+          sender: ""
+          description: ""
+          trigger: ""
+          data: ""
+          destination: WEBSITE/GOOGLE_OWNED_SERVICE/OTHER
+        }
+        policy {
+          cookies_allowed: false/true
+          cookies_store_exceptions: ""
+          setting: ""
+          policy {
+            [POLICY_NAME] {
+                policy_options {mode: MANDATORY/RECOMMENDED/UNSET}
+                value: ...
+            }
+          }
+        })");
+  fetcher_.reset(URLFetcher::Create(url,
+                                    URLFetcher::GET,
+                                    this,
+                                    traffic_annotation).release());
+
   fetcher_->SetRequestContext(request_context);
   fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                          net::LOAD_DO_NOT_SAVE_COOKIES);