Convert BlockFiles to use FilePath instead of wstring.

net/disk_cache/backend_impl.h

Index: net/disk_cache/backend_impl.h
diff --git a/net/disk_cache/backend_impl.h b/net/disk_cache/backend_impl.h
index 00711a98e747e0b3ac0580010363a55361cd1719..85075db6d3f890b7a00ad5aa018e8cf2e635c002 100644
--- a/net/disk_cache/backend_impl.h
+++ b/net/disk_cache/backend_impl.h
@@ -36,14 +36,14 @@ class BackendImpl : public Backend {
   friend class Eviction;
  public:
   explicit BackendImpl(const FilePath& path)
-      : path_(path), block_files_(path.ToWStringHack()), mask_(0), max_size_(0),
+      : path_(path), block_files_(path), mask_(0), max_size_(0),
         cache_type_(net::DISK_CACHE), uma_report_(0), user_flags_(0),
         init_(false), restarted_(false), unit_test_(false), read_only_(false),
         new_eviction_(false), first_timer_(true),
         ALLOW_THIS_IN_INITIALIZER_LIST(factory_(this)) {}
   // mask can be used to limit the usable size of the hash table, for testing.
   BackendImpl(const FilePath& path, uint32 mask)
-      : path_(path), block_files_(path.ToWStringHack()), mask_(mask), max_size_(0),
+      : path_(path), block_files_(path), mask_(mask), max_size_(0),
         cache_type_(net::DISK_CACHE), uma_report_(0), user_flags_(kMask),
         init_(false), restarted_(false), unit_test_(false), read_only_(false),
         new_eviction_(false), first_timer_(true),