Reorganize net/disk_cache into backend specific directories.

net/disk_cache/blockfile/backend_impl.cc

Index: net/disk_cache/blockfile/backend_impl.cc
diff --git a/net/disk_cache/backend_impl.cc b/net/disk_cache/blockfile/backend_impl.cc
similarity index 99%
rename from net/disk_cache/backend_impl.cc
rename to net/disk_cache/blockfile/backend_impl.cc
index c4356fba4615b108ae583aade4cd992bc557aec6..f83038fe619ab39d5033772c69adec0088b8ed1c 100644
--- a/net/disk_cache/backend_impl.cc
+++ b/net/disk_cache/blockfile/backend_impl.cc
@@ -2,7 +2,7 @@
 // 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 "net/disk_cache/blockfile/backend_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ -21,15 +21,15 @@
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "net/base/net_errors.h"
+#include "net/disk_cache/blockfile/disk_format.h"
+#include "net/disk_cache/blockfile/entry_impl.h"
+#include "net/disk_cache/blockfile/errors.h"
+#include "net/disk_cache/blockfile/experiments.h"
+#include "net/disk_cache/blockfile/file.h"
 #include "net/disk_cache/cache_util.h"
-#include "net/disk_cache/disk_format.h"
-#include "net/disk_cache/entry_impl.h"
-#include "net/disk_cache/errors.h"
-#include "net/disk_cache/experiments.h"
-#include "net/disk_cache/file.h"
 
 #define CACHE_HISTOGRAM_MACROS_BACKEND_IMPL_OBJ this
-#include "net/disk_cache/histogram_macros.h"
+#include "net/disk_cache/blockfile/histogram_macros.h"
 
 using base::Time;
 using base::TimeDelta;