Make URLRequest::Read to return net errors or bytes read instead of a bool

net/base/layered_network_delegate.h

Index: net/base/layered_network_delegate.h
diff --git a/net/base/layered_network_delegate.h b/net/base/layered_network_delegate.h
index ba7ecc710f9805e3b35fa52f616aa1f2b265e44b..0c0ff9bacbf898e1979a349a59197b6f41930353 100644
--- a/net/base/layered_network_delegate.h
+++ b/net/base/layered_network_delegate.h
@@ -59,10 +59,15 @@ class NET_EXPORT LayeredNetworkDelegate : public NetworkDelegate {
       scoped_refptr<HttpResponseHeaders>* override_response_headers,
       GURL* allowed_unsafe_redirect_url) final;
   void OnBeforeRedirect(URLRequest* request, const GURL& new_location) final;
+
+  void OnResponseStarted(URLRequest* request, int net_error) final;
+  // Deprecated.
   void OnResponseStarted(URLRequest* request) final;
   void OnNetworkBytesReceived(URLRequest* request,
                               int64_t bytes_received) final;
   void OnNetworkBytesSent(URLRequest* request, int64_t bytes_sent) final;
+  void OnCompleted(URLRequest* request, bool started, int net_error) final;
+  // Deprecated.
   void OnCompleted(URLRequest* request, bool started) final;
   void OnURLRequestDestroyed(URLRequest* request) final;
   void OnPACScriptError(int line_number, const base::string16& error) final;