**STILLBAKING** Decouple disk cache tests from backends.

net/disk_cache/disk_cache_test_util.cc

Index: net/disk_cache/disk_cache_test_util.cc
diff --git a/net/disk_cache/disk_cache_test_util.cc b/net/disk_cache/disk_cache_test_util.cc
index 2b23ee4d8bfad701e5d9f5141168afcf8b193579..9d36c13b8061c1ae4288190aef41e1a8cd6c12c5 100644
--- a/net/disk_cache/disk_cache_test_util.cc
+++ b/net/disk_cache/disk_cache_test_util.cc
@@ -46,12 +46,11 @@ bool CreateCacheTestFile(const base::FilePath& name) {
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE;
 
-  scoped_refptr<disk_cache::File> file(new disk_cache::File(
-      base::CreatePlatformFile(name, flags, NULL, NULL)));
-  if (!file->IsValid())
+  base::PlatformFile file = base::CreatePlatformFile(name, flags, NULL, NULL);
+  if (file == base::kInvalidPlatformFileValue)
     return false;
 
-  file->SetLength(4 * 1024 * 1024);
+  base::TruncatePlatformFile(file, 4 * 1024 * 1024);
   return true;
 }
 
@@ -60,20 +59,6 @@ bool DeleteCache(const base::FilePath& path) {
   return true;
 }
 
-bool CheckCacheIntegrity(const base::FilePath& path, bool new_eviction,
-                         uint32 mask) {
-  scoped_ptr<disk_cache::BackendImpl> cache(new disk_cache::BackendImpl(
-      path, mask, base::MessageLoopProxy::current().get(), NULL));
-  if (!cache.get())
-    return false;
-  if (new_eviction)
-    cache->SetNewEviction();
-  cache->SetFlags(disk_cache::kNoRandom);
-  if (cache->SyncInit() != net::OK)
-    return false;
-  return cache->SelfCheck() >= 0;
-}
-
 // -----------------------------------------------------------------------
 
 MessageLoopHelper::MessageLoopHelper()