Select precache resources based on field trial experiment group

components/precache/core/precache_fetcher.h

 // Copyright 2013 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 COMPONENTS_PRECACHE_CORE_PRECACHE_FETCHER_H_
 #define COMPONENTS_PRECACHE_CORE_PRECACHE_FETCHER_H_
 
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 87 matching lines @@
 
   static void RecordCompletionStatistics(
       const PrecacheUnfinishedWork& unfinished_work,
       size_t remaining_manifest_urls_to_fetch,
       size_t remaining_resource_urls_to_fetch);
 
   // Constructs a new PrecacheFetcher. The |starting_hosts| parameter is a
   // prioritized list of hosts that the user commonly visits. These hosts are
   // used by a server side component to construct a list of resource URLs that
   // the user is likely to fetch. Takes ownership of |unfinished_work|.
-  PrecacheFetcher(
-      net::URLRequestContextGetter* request_context,
-      const GURL& config_url,
-      const std::string& manifest_url_prefix,
-      std::unique_ptr<PrecacheUnfinishedWork> unfinished_work,
-      PrecacheDelegate* precache_delegate);
+  PrecacheFetcher(net::URLRequestContextGetter* request_context,
+                  const GURL& config_url,
+                  const std::string& manifest_url_prefix,
+                  std::unique_ptr<PrecacheUnfinishedWork> unfinished_work,
+                  uint32_t experiment_id,
+                  PrecacheDelegate* precache_delegate);
 
   virtual ~PrecacheFetcher();
 
   // Starts fetching resources to precache. URLs are fetched sequentially. Can
   // be called from any thread. Start should only be called once on a
   // PrecacheFetcher instance.
   void Start();
 
   // Stops all precaching work. The PreacheFetcher should not be used after
   // calling this method.
@@ skipping 48 matching lines @@
   // Non-owning pointer. Should not be NULL.
   PrecacheDelegate* precache_delegate_;
 
   std::list<GURL> manifest_urls_to_fetch_;
   std::list<GURL> resource_urls_to_fetch_;
 
   FetcherPool<Fetcher> pool_;
 
   std::unique_ptr<PrecacheUnfinishedWork> unfinished_work_;
 
+  // The fieldtrial experiment ID.
+  uint32_t experiment_id_;
+
   DISALLOW_COPY_AND_ASSIGN(PrecacheFetcher);
 };
 
 // Class that fetches a URL, and runs the specified callback when the fetch is
 // complete. This class exists so that a different method can be run in
 // response to different kinds of fetches, e.g. OnConfigFetchComplete when
 // configuration settings are fetched, OnManifestFetchComplete when a manifest
 // is fetched, etc.
 //
 // This class tries to increase freshness while limiting network usage, by using
@@ skipping 50 matching lines @@
   std::unique_ptr<net::URLFetcher> network_url_fetcher_;
   int64_t response_bytes_;
   int64_t network_response_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(Fetcher);
 };
 
 }  // namespace precache
 
 #endif  // COMPONENTS_PRECACHE_CORE_PRECACHE_FETCHER_H_