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 c934b87c8acd09bd8ce5394ada19e57b72a49be7..85c4e36c1f3c5fff79290b0180e6db9d9ccfeae1 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"
@@ -21,13 +21,13 @@
 #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/blockfile/histogram_macros.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"
-#include "net/disk_cache/histogram_macros.h"
 
 // Provide a BackendImpl object to macros from histogram_macros.h.
 #define CACHE_UMA_BACKEND_IMPL_OBJ this