Avoid doing periodic prerender cleanup when there are no contents.

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 <list>
 #include <map>
 #include <string>
@@ skipping 71 matching lines @@
   // NOTE: New values need to be appended, since they are used in histograms.
   enum PrerenderManagerMode {
     PRERENDER_MODE_DISABLED = 0,
     PRERENDER_MODE_ENABLED = 1,
     PRERENDER_MODE_EXPERIMENT_CONTROL_GROUP = 2,
     PRERENDER_MODE_EXPERIMENT_PRERENDER_GROUP = 3,
     // Obsolete: PRERENDER_MODE_EXPERIMENT_5MIN_TTL_GROUP = 4,
     PRERENDER_MODE_EXPERIMENT_NO_USE_GROUP = 5,
     PRERENDER_MODE_EXPERIMENT_MULTI_PRERENDER_GROUP = 6,
     PRERENDER_MODE_EXPERIMENT_15MIN_TTL_GROUP = 7,
+    PRERENDER_MODE_EXPERIMENT_MATCH_COMPLETE_GROUP = 8,
     PRERENDER_MODE_MAX
   };
 
   // One or more of these flags must be passed to ClearData() to specify just
   // what data to clear.  See function declaration for more information.
   enum ClearFlags {
     CLEAR_PRERENDER_CONTENTS = 0x1 << 0,
     CLEAR_PRERENDER_HISTORY = 0x1 << 1,
     CLEAR_MAX = 0x1 << 2
   };
@@ skipping 633 matching lines @@
   bool cookie_store_loaded_;
 
   base::Closure on_cookie_store_loaded_cb_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderManager);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_