Use more flexible field trial control on resource prefetching for mobile web

chrome/browser/predictors/resource_prefetch_common.h

 // Copyright 2014 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_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
 #define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_
 
 #include "base/time/time.h"
 #include "url/gurl.h"
 
@@ skipping 56 matching lines @@
   enum Mode {
     URL_LEARNING    = 1 << 0,
     HOST_LEARNING   = 1 << 1,
     URL_PREFETCHING = 1 << 2,  // Should also turn on URL_LEARNING.
     HOST_PRFETCHING = 1 << 3   // Should also turn on HOST_LEARNING.
   };
   int mode;
 
   // Helpers to deal with mode.
   bool IsLearningEnabled() const;
-  bool IsPrefetchingEnabled() const;
+  bool IsPrefetchingEnabled(Profile* profile) const;
   bool IsURLLearningEnabled() const;
   bool IsHostLearningEnabled() const;
-  bool IsURLPrefetchingEnabled() const;
-  bool IsHostPrefetchingEnabled() const;
+  bool IsURLPrefetchingEnabled(Profile* profile) const;
+  bool IsHostPrefetchingEnabled(Profile* profile) const;
+
+  bool IsLowConfidenceForTest() const;
+  bool IsHighConfidenceForTest() const;
+  bool IsMoreResourcesEnabledForTest() const;
+  bool IsSmallDBEnabledForTest() const;
 
   // If a navigation hasn't seen a load complete event in this much time, it
   // is considered abandoned.
   size_t max_navigation_lifetime_seconds;
 
   // Size of LRU caches for the URL and host data.
   size_t max_urls_to_track;
   size_t max_hosts_to_track;
 
   // The number of times we should have seen a visit to this URL in history
@@ skipping 15 matching lines @@
   // Maximum number of prefetches that can be inflight for a single navigation.
   size_t max_prefetches_inflight_per_navigation;
   // Maximum number of prefetches that can be inflight for a host for a single
   // navigation.
   size_t max_prefetches_inflight_per_host_per_navigation;
 };
 
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_COMMON_H_