Clean up dependencies for disk_cache histogram_macros.h.

net/disk_cache/eviction.cc

 // 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.
 
 // The eviction policy is a very simple pure LRU, so the elements at the end of
 // the list are evicted until kCleanUpMargin free space is available. There is
 // only one list in use (Rankings::NO_USE), and elements are sent to the front
 // of the list whenever they are accessed.
 
 // The new (in-development) eviction policy adds re-use as a factor to evict
@@ skipping 23 matching lines @@
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "base/time/time.h"
 #include "net/disk_cache/backend_impl.h"
 #include "net/disk_cache/disk_format.h"
 #include "net/disk_cache/entry_impl.h"
 #include "net/disk_cache/experiments.h"
 #include "net/disk_cache/histogram_macros.h"
 #include "net/disk_cache/trace.h"
 
+// Provide a BackendImpl object to macros from histogram_macros.h.
+#define CACHE_UMA_BACKEND_IMPL_OBJ backend_
+
 using base::Time;
 using base::TimeTicks;
 
 namespace {
 
 const int kCleanUpMargin = 1024 * 1024;
 const int kHighUse = 10;  // Reuse count to be on the HIGH_USE list.
 const int kTargetTime = 24 * 7;  // Time to be evicted (hours since last use).
 const int kMaxDelayedTrims = 60;
 
@@ skipping 534 matching lines @@
               Time::FromInternalValue(last2.get()->Data()->last_used));
   if (last3.get())
     CACHE_UMA(AGE, "HighUseAge", 0,
               Time::FromInternalValue(last3.get()->Data()->last_used));
   if (last4.get())
     CACHE_UMA(AGE, "DeletedAge", 0,
               Time::FromInternalValue(last4.get()->Data()->last_used));
 }
 
 }  // namespace disk_cache