Experiment to disable Prerendering with fast wind-down

chrome/browser/prerender/prerender_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_MANAGER_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 303 matching lines @@
   // from a prerendering perspective. Currently, if Prerender Cookie Stores are
   // enabled, prerenders must be in their own processes that may not be shared.
   bool MayReuseProcessHost(content::RenderProcessHost* process_host);
 
   // content::RenderProcessHostObserver implementation.
   void RenderProcessHostDestroyed(content::RenderProcessHost* host) override;
 
   void SetPrerenderContentsFactoryForTest(
       PrerenderContents::Factory* prerender_contents_factory);
 
+  bool IsPrerenderSilenceExperimentForTesting(Origin origin) const {
+    return IsPrerenderSilenceExperiment(origin);
+  }
+
  protected:
   class PrerenderData : public base::SupportsWeakPtr<PrerenderData> {
    public:
     struct OrderByExpiryTime;
 
     PrerenderData(PrerenderManager* manager,
                   std::unique_ptr<PrerenderContents> contents,
                   base::TimeTicks expiry_time);
 
     ~PrerenderData();
@@ skipping 65 matching lines @@
   class OnCloseWebContentsDeleter;
   struct NavigationRecord;
   using PrerenderDataVector = std::vector<std::unique_ptr<PrerenderData>>;
 
   // Time interval before a new prerender is allowed.
   static const int kMinTimeBetweenPrerendersMs = 500;
 
   // Time window for which we record old navigations, in milliseconds.
   static const int kNavigationRecordWindowMs = 5000;
 
+  // Returns whether adding new prerenders should be disabled because of the
+  // experiment running.
+  bool IsPrerenderSilenceExperiment(Origin origin) const;
+
   // Returns whether prerendering is currently enabled or the reason why it is
   // disabled.
   chrome_browser_net::NetworkPredictionStatus GetPredictionStatus() const;
 
   // Returns whether prerendering is currently enabled or the reason why it is
   // disabled after taking into account the origin of the request.
   chrome_browser_net::NetworkPredictionStatus GetPredictionStatusForOrigin(
       Origin origin) const;
 
   // Adds a prerender for |url| from |referrer|. The |origin| specifies how the
@@ skipping 144 matching lines @@
   // Set of process hosts being prerendered.
   using PrerenderProcessSet = std::set<content::RenderProcessHost*>;
   PrerenderProcessSet prerender_process_hosts_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderManager);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_