[Mojo-Loading] Implement URLLoader::SetPriority

content/common/url_loader.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module content.mojom;
 
 [Native]
 struct URLRequest;
 
 [Native]
 struct URLResponseHead;
 
 [Native]
 struct URLRequestRedirectInfo;
 
 [Native]
 struct URLLoaderStatus;
 
+// This enum corresponds to net::RequestPriority. See its comments for details.
+enum RequestPriority {
+  kThrottled = 0,
+  kIdle,
+  kLowest,
+  kLow,
+  kMedium,
+  kHighest
+};
+
 // Destroying a URLLoader will cancel the associated request.
 interface URLLoader {
   // If the associated request has |auto_follow_redirects| set to false,
   // then upon receiving an URLResponse with a non-NULL |redirect_url| field,
   // |FollowRedirect| may be called to load the URL indicated by the redirect.
   FollowRedirect();
+
+  // Sets the request priority.
+  // |intra_priority_value| is a lesser priority which is used to prioritize
+  // requests within a given priority level.
+  SetPriority(RequestPriority priority, int32 intra_priority_value);
 };
 
 // Opaque handle passed from the browser process to a child process to manage
 // the lifetime of temporary files used for download_to_file resource loading.
 // When the message pipe for this interface is closed, the browser process will
 // clean up the corresponding temporary file.
 interface DownloadedTempFile {
 };
 
 
@@ skipping 36 matching lines @@
 
   // Called when the loader starts loading response body. This is called after
   // OnReceiveResponse is called.
   OnStartLoadingResponseBody(handle<data_pipe_consumer> body);
 
   // Called when the loading completes. No notification will be dispatched for
   // this client after this message arrives.
   OnComplete(URLLoaderStatus completion_status);
 };