Deflake Simple Cache backend on Windows.

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 e06efd953fa7a47eac5f1560c214b07b620f5dda..bb313ed39d2075d060f0f88ebdeb370d71143d5b 100644
--- a/net/disk_cache/backend_unittest.cc
+++ b/net/disk_cache/backend_unittest.cc
@@ -3144,11 +3144,6 @@ TEST_F(DiskCacheBackendTest, ShaderCacheUpdateRankForExternalCacheHit) {
   entry->Close();
 }
 
-// The Simple Cache backend requires a few guarantees from the filesystem like
-// atomic renaming of recently open files. Those guarantees are not provided in
-// general on Windows.
-#if defined(OS_POSIX)
-
 TEST_F(DiskCacheBackendTest, SimpleCacheShutdownWithPendingCreate) {
   SetCacheType(net::APP_CACHE);
   SetSimpleCacheMode();
@@ -3486,5 +3481,3 @@ TEST_F(DiskCacheBackendTest, SimpleCacheEnumerationDestruction) {
   cache_.reset();
   // This test passes if we don't leak memory.
 }
-
-#endif  // defined(OS_POSIX)