Clean up dependencies for disk_cache histogram_macros.h.

net/disk_cache/v3/eviction_v3.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 22 matching lines @@
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "base/time/time.h"
 #include "net/disk_cache/experiments.h"
 #include "net/disk_cache/trace.h"
 #include "net/disk_cache/v3/backend_impl_v3.h"
 #include "net/disk_cache/v3/entry_impl_v3.h"
 #include "net/disk_cache/v3/histogram_macros.h"
 
+// Define CACHE_UMA_BACKEND_IMPL_OBJ to be a disk_cache::BackendImpl* in order
+// to use the CACHE_UMA histogram macro.
+#define CACHE_UMA_BACKEND_IMPL_OBJ backend_
 
 using base::Time;
 using base::TimeTicks;
 
 namespace {
 
 const int kCleanUpMargin = 1024 * 1024;
 
 #if defined(V3_NOT_JUST_YET_READY)
 const int kHighUse = 10;  // Reuse count to be on the HIGH_USE list.
@@ skipping 449 matching lines @@
   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));
 }
 #endif  // defined(V3_NOT_JUST_YET_READY).
 
 }  // namespace disk_cache