Send privet auth token in PrivetV3 mode instead of X-Privet token

chrome/browser/local_discovery/privet_url_fetcher.h

Index: chrome/browser/local_discovery/privet_url_fetcher.h
diff --git a/chrome/browser/local_discovery/privet_url_fetcher.h b/chrome/browser/local_discovery/privet_url_fetcher.h
index 5b2b80ca28733bcbe2042e098ecb5260f8e4ce19..698ca09208d151afd010c7ecfb10efc43c5db098 100644
--- a/chrome/browser/local_discovery/privet_url_fetcher.h
+++ b/chrome/browser/local_discovery/privet_url_fetcher.h
@@ -42,11 +42,15 @@ class PrivetURLFetcher : public net::URLFetcherDelegate {
    public:
     virtual ~Delegate() {}
 
-    // If you do not implement this method, you will always get a
-    // TOKEN_ERROR error when your token is invalid.
+    // If you do not implement this method for PrivetV1 callers, you will always
+    // get a TOKEN_ERROR error when your token is invalid.
     virtual void OnNeedPrivetToken(
         PrivetURLFetcher* fetcher,
         const TokenCallback& callback);
+
+    // If this returns the empty string, will not send an auth token.
+    virtual std::string GetAuthToken();
+
     virtual void OnError(PrivetURLFetcher* fetcher, ErrorType error) = 0;
     virtual void OnParsedJson(PrivetURLFetcher* fetcher,
                               const base::DictionaryValue& value,
@@ -81,6 +85,8 @@ class PrivetURLFetcher : public net::URLFetcherDelegate {
 
   void SendEmptyPrivetToken();
 
+  void V3Mode();
+
   // Set the contents of the Range header. |OnRawData| must return true if this
   // is called.
   void SetByteRange(int start, int end);
@@ -121,6 +127,7 @@ class PrivetURLFetcher : public net::URLFetcherDelegate {
   bool send_empty_privet_token_;
   bool has_byte_range_;
   bool make_response_file_;
+  bool v3_mode_;
 
   int byte_range_start_;
   int byte_range_end_;