Change multi-prerender API to include per launcher slots.

chrome/browser/prerender/prerender_config.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_CONFIG_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_CONFIG_H_
 
 #include <string>
 
 #include "base/time.h"
 #include "ui/gfx/rect.h"
 
 namespace prerender {
 
 struct Config {
   Config();
   ~Config();
 
   // Maximum memory use for a prerendered page until it is killed.
   size_t max_bytes;
 
-  // Number of simultaneous prendered pages allowed.
-  size_t max_concurrency;
+  // Number of simultaneous prerender pages from link elements allowed. Enforced
+  // by PrerenderLinkManager.
+  size_t max_link_concurrency;
+
+  // Number of simultaneous prerender pages from link elements allowed per
+  // launching page. Enforced by PrerenderLinkManager.
+  size_t max_link_concurrency_per_launcher;
 
   // Is rate limiting enabled?
   bool rate_limit_enabled;
 
+  // The maximum time that a prerender can wait for launch in the
+  // PrerenderLinkManager.
+  base::TimeDelta max_wait_to_launch;
+
   // The default time to live of a newly created prerender. May be shortened to
   // abandon_time_to_live, below.
   base::TimeDelta time_to_live;
 
   // After a prerender has been abandoned by the user navigating away from the
   // source page or otherwise mooting the launcher, how long until the prerender
   // should be removed. This exists because a prerendered page is often
   // navigated to through a chain of redirects; removing the prerender when the
   // link element is removed because of navigation would destroy prerenders just
   // before they were going to be used.
@@ skipping 10 matching lines @@
   std::string user_agent_override;
 
   // Is the user agent being overridden for this NavigationEntry?
   bool is_overriding_user_agent;
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_CONFIG_H_