Start migrating the disk cache to using FilePath.

net/disk_cache/backend_unittest.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
 #include "base/string_util.h"
 #include "net/base/io_buffer.h"
@@ skipping 1413 matching lines @@
   InitCache();
   BackendDisable4();
 }
 
 TEST_F(DiskCacheTest, Backend_UsageStats) {
   MessageLoopHelper helper;
 
   std::wstring path = GetCachePath();
   ASSERT_TRUE(DeleteCache(path.c_str()));
   scoped_ptr<disk_cache::BackendImpl> cache;
-  cache.reset(new disk_cache::BackendImpl(path));
+  cache.reset(new disk_cache::BackendImpl(FilePath::FromWStringHack(path)));
   ASSERT_TRUE(NULL != cache.get());
   cache->SetUnitTestMode();
   ASSERT_TRUE(cache->Init());
 
   // Wait for a callback that never comes... about 2 secs :). The message loop
   // has to run to allow invocation of the usage timer.
   helper.WaitUntilCacheIoFinished(1);
 }
 
 void DiskCacheBackendTest::BackendDoomAll() {
@@ skipping 127 matching lines @@
   EXPECT_EQ(kDefaultSize * 5 / 2,
             disk_cache::PreferedCacheSize(large_size * 100 / 2));
   EXPECT_EQ(kDefaultSize * 5 / 2,
             disk_cache::PreferedCacheSize(large_size * 500 / 2));
 
   EXPECT_EQ(kDefaultSize * 6 / 2,
             disk_cache::PreferedCacheSize(large_size * 600 / 2));
   EXPECT_EQ(kDefaultSize * 7 / 2,
             disk_cache::PreferedCacheSize(large_size * 700 / 2));
 }