SimpleCache: synchronously reply on reads from idle if data is in memory.

net/disk_cache/simple/simple_entry_impl.h

 // Copyright (c) 2013 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.
 
 #ifndef NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_IMPL_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 174 matching lines @@
   void OpenEntryInternal(bool have_index,
                          const CompletionCallback& callback,
                          Entry** out_entry);
 
   void CreateEntryInternal(bool have_index,
                            const CompletionCallback& callback,
                            Entry** out_entry);
 
   void CloseInternal();
 
-  void ReadDataInternal(int index,
-                        int offset,
-                        net::IOBuffer* buf,
-                        int buf_len,
-                        const CompletionCallback& callback);
+  int ReadDataInternal(bool try_sync,
+                       int index,
+                       int offset,
+                       net::IOBuffer* buf,
+                       int buf_len,
+                       const CompletionCallback& callback);
 
   void WriteDataInternal(int index,
                          int offset,
                          net::IOBuffer* buf,
                          int buf_len,
                          const CompletionCallback& callback,
                          bool truncate);
 
   void ReadSparseDataInternal(int64_t sparse_offset,
                               net::IOBuffer* buf,
@@ skipping 175 matching lines @@
   // 1 on disk, to reduce the number of file descriptors and save disk space.
   // This strategy allows stream 1 to change size easily. Since stream 0 is only
   // used to write HTTP headers, the memory consumption of keeping it in memory
   // is acceptable.
   scoped_refptr<net::GrowableIOBuffer> stream_0_data_;
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_IMPL_H_