Reorganize net/disk_cache into backend specific directories.

net/disk_cache/backend_unittest.cc

Index: net/disk_cache/backend_unittest.cc
diff --git a/net/disk_cache/backend_unittest.cc b/net/disk_cache/backend_unittest.cc
index 1058c0c54df16efe7aaafb7ad3a446c446f4ca59..213c414305d0bbce98c73f3b7188ed8b5375727e 100644
--- a/net/disk_cache/backend_unittest.cc
+++ b/net/disk_cache/backend_unittest.cc
@@ -15,19 +15,19 @@
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/test_completion_callback.h"
-#include "net/disk_cache/backend_impl.h"
+#include "net/disk_cache/blockfile/backend_impl.h"
+#include "net/disk_cache/blockfile/entry_impl.h"
+#include "net/disk_cache/blockfile/experiments.h"
+#include "net/disk_cache/blockfile/mapped_file.h"
 #include "net/disk_cache/cache_util.h"
 #include "net/disk_cache/disk_cache_test_base.h"
 #include "net/disk_cache/disk_cache_test_util.h"
-#include "net/disk_cache/entry_impl.h"
-#include "net/disk_cache/experiments.h"
-#include "net/disk_cache/mapped_file.h"
-#include "net/disk_cache/mem_backend_impl.h"
+#include "net/disk_cache/memory/mem_backend_impl.h"
 #include "net/disk_cache/simple/simple_backend_impl.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 #include "net/disk_cache/simple/simple_test_util.h"
 #include "net/disk_cache/simple/simple_util.h"
-#include "net/disk_cache/tracing_cache_backend.h"
+#include "net/disk_cache/tracing/tracing_cache_backend.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_WIN)
@@ -35,7 +35,7 @@
 #endif
 
 #define CACHE_HISTOGRAM_MACROS_BACKEND_IMPL_OBJ backend_
-#include "net/disk_cache/histogram_macros.h"
+#include "net/disk_cache/blockfile/histogram_macros.h"
 
 using base::Time;