base::Bind: Convert FileUtilProxy::ReadCallback.

base/file_util_proxy.h

Index: base/file_util_proxy.h
diff --git a/base/file_util_proxy.h b/base/file_util_proxy.h
index 306d2e46f83dd03be5a80c42cbab397c5f10ecba..afa36a0019d74655fa6334055216899ac8318be9 100644
--- a/base/file_util_proxy.h
+++ b/base/file_util_proxy.h
@@ -52,9 +52,9 @@ class BASE_EXPORT FileUtilProxy {
       GetFileInfoCallback;
   typedef base::Callback<void(PlatformFileError /* error code */,
                               const std::vector<Entry>&)> ReadDirectoryCallback;
-  typedef Callback3<PlatformFileError /* error code */,
-                    const char* /* data */,
-                    int /* bytes read/written */>::Type ReadCallback;
+  typedef base::Callback<void(PlatformFileError /* error code */,
+                              const char* /* data */,
+                              int /* bytes read/written */)> ReadCallback;
   typedef Callback2<PlatformFileError /* error code */,
                     int /* bytes written */>::Type WriteCallback;
 
@@ -161,13 +161,13 @@ class BASE_EXPORT FileUtilProxy {
       StatusCallback* callback);
 
   // Reads from a file. On success, the file pointer is moved to position
-  // |offset + bytes_to_read| in the file. The callback can be NULL.
+  // |offset + bytes_to_read| in the file. The callback can be null.
   static bool Read(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       int64 offset,
       int bytes_to_read,
-      ReadCallback* callback);
+      const ReadCallback& callback);
 
   // Writes to a file. If |offset| is greater than the length of the file,
   // |false| is returned. On success, the file pointer is moved to position