Clean up dependencies for disk_cache histogram_macros.h.

net/disk_cache/v3/histogram_macros.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.
 
 // This file contains macros to simplify histogram reporting from the disk
 // cache. The main issue is that we want to have separate histograms for each
 // type of cache (regular vs. media, etc), without adding the complexity of
 // keeping track of a potentially large number of histogram objects that have to
 // survive the backend object that created them.
 
@@ skipping 66 matching lines @@
                                  (base::Time::Now() - initial_time).InHours())
 
 // HISTOGRAM_AGE_MS will collect time elapsed since |initial_time|, with the
 // normal resolution of the UMA_HISTOGRAM_TIMES.
 #define CACHE_HISTOGRAM_AGE_MS(name, initial_time)\
     CACHE_HISTOGRAM_TIMES(name, base::TimeTicks::Now() - initial_time)
 
 #define CACHE_HISTOGRAM_CACHE_ERROR(name, sample) \
     CACHE_HISTOGRAM_ENUMERATION(name, sample, 50)
 
-#ifdef NET_DISK_CACHE_BACKEND_IMPL_CC_
-#define BACKEND_OBJ this
-#else
-#define BACKEND_OBJ backend_
-#endif
+#define BACKEND_OBJ CACHE_HISTOGRAM_MACROS_BACKEND_IMPL_OBJ
 
 // Generates a UMA histogram of the given type, generating the proper name for
 // it (asking backend_->HistogramName), and adding the provided sample.
 // For example, to generate a regualar UMA_HISTOGRAM_COUNTS, this macro would
 // be used as:
 //  CACHE_UMA(COUNTS, "MyName", 20);
 // which may translate to:
 //  UMA_HISTOGRAM_COUNTS("DiskCache3.MyName_AppCache", 20);
 //
 #define CACHE_UMA(type, name, sample) {\
@@ skipping 13 matching lines @@
         break;\
       case net::PNACL_CACHE:\
         CACHE_HISTOGRAM_##type(my_name.data(), sample);\
         break;\
       default:\
         break;\
     }\
   }
 
 #endif  // NET_DISK_CACHE_V3_HISTOGRAM_MACROS_H_