disable field trials if the build is 30 days or older

net/disk_cache/backend_impl.cc

 // Copyright (c) 2010 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.
 
 #include "net/disk_cache/backend_impl.h"
 
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/metrics/field_trial.h"
@@ skipping 164 matching lines @@
   // Field trials involve static objects so we have to do this only once.
   first = false;
   scoped_refptr<base::FieldTrial> trial1(
       new base::FieldTrial("CacheSize", 10));
   std::string group1 = base::StringPrintf("CacheSizeGroup_%d", size_group);
   trial1->AppendGroup(group1, base::FieldTrial::kAllRemainingProbability);
 
   scoped_refptr<base::FieldTrial> trial2(
       new base::FieldTrial("CacheThrottle", 100));
   int group2a = trial2->AppendGroup("CacheThrottle_On", 10);  // 10 % in.
-  trial2->AppendGroup("CacheThrottle_Off", 10);  // 10 % control.
+  trial2->AppendGroup("CacheThrottle_Off",
+      base::FieldTrial::kAllRemainingProbability);  // 90 % control.
 
   return trial2->group() == group2a;
 }
 
 // ------------------------------------------------------------------------
 
 // This class takes care of building an instance of the backend.
 class CacheCreator {
  public:
   CacheCreator(const FilePath& path, bool force, int max_bytes,
@@ skipping 1899 matching lines @@
     if (total_memory > kMaxBuffersSize || total_memory <= 0)
       total_memory = kMaxBuffersSize;
 
     done = true;
   }
 
   return static_cast<int>(total_memory);
 }
 
 }  // namespace disk_cache