**NOTFORLANDING** New link rel=prerender API

chrome/browser/prerender/prerender_link_manager.h

+// Copyright (c) 2012 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.
+
+#ifndef CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_
+#pragma once
+
+#include <map>
+#include <utility>
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "chrome/browser/profiles/profile_keyed_service.h"
+#include "googleurl/src/gurl.h"
+
+class Profile;
+
+namespace content {
+struct Referrer;
+}
+
+namespace gfx {
+class Size;
+}
+
+namespace prerender {
+
+class PrerenderManager;
+
+// Launch and cancel prerenders based on the LinkPrerender element events.

[cbentzel, 2012/04/24 15:42:59]

I'd prefer a bit more description here.

[gavinp, 2012/04/26 23:55:39]

Done.

+class PrerenderLinkManager : public ProfileKeyedService {
+ public:
+  explicit PrerenderLinkManager(PrerenderManager* manager);
+  virtual ~PrerenderLinkManager();
+
+  // A <link rel=prerender ...> element has been inserted into the document.
+  void OnAddPrerender(
+      int prerender_id,
+      int child_id,

[mmenke, 2012/04/24 15:26:15]

nit:  I suggest always putting child_id first.  This is both the order of the id
pair, and it makes more sense to have the "more significant" id first.

[gavinp, 2012/04/26 23:55:39]

Done.

+      const GURL& url,
+      const content::Referrer& referrer,
+      const gfx::Size& size,
+      int render_view_route_id);
+
+  // A <link rel=prerender ...> element has been explicitly removed from a
+  // document.
+  void OnCancelPrerender(int prerender_id, int child_id);
+
+  // A renderer launching <link rel=prerender ...> has navigated away from the
+  // launching page, the launching renderer process has crashed, or perhaps the
+  // renderer processed was fast-closed when the last render view in it was

[cbentzel, 2012/04/24 15:42:59]

Nit: renderer process

[gavinp, 2012/04/26 23:55:39]

Done.

+  // closed.
+  void OnAbandonPrerender(int prerender_id, int child_id);
+
+  // If a renderer channel closes (crash, fast exit, etc...), that's effectively
+  // an abandon of any prerenders launched by that child.
+  void OnChannelClosing(int child_id);
+
+ private:
+  typedef std::pair<int, int> ChildAndPrerenderIdPair;
+  typedef std::map<ChildAndPrerenderIdPair, GURL> PrerenderIdToUrlMap;

[mmenke, 2012/04/24 15:26:15]

nit:  Suggest you rename this either IdToUrlMap, IdPairToUrlMap,
PrerenderIdsToUrlMap, or some such.  Just make clear it's not just a
prerender_id.  And a corresponding change to the other typedef, of course.

[gavinp, 2012/04/26 23:55:39]

Done.

+  typedef std::multimap<GURL, ChildAndPrerenderIdPair> UrlToPrerenderIdMap;
+
+  void RemovePrerender(const PrerenderIdToUrlMap::iterator& id_url_iter);
+
+  PrerenderManager* manager_;
+  PrerenderIdToUrlMap id_map_;
+  UrlToPrerenderIdMap url_map_;

[mmenke, 2012/04/24 15:26:15]

nit:  Suggest you rename these ids_to_url_map_, etc.  It's not uncommon to name
maps after the values instead of the keys.  In fact, a quick search indicates
that naming maps after the values may be more common.

[gavinp, 2012/04/26 23:55:39]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(PrerenderLinkManager);
+};
+
+}  // namespace prerender
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_