Refactor StringPiece hash.

net/spdy/spdy_header_block.h

 // Copyright (c) 2012 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_SPDY_SPDY_HEADER_BLOCK_H_
 #define NET_SPDY_SPDY_HEADER_BLOCK_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 17 matching lines @@
 // Under the hood, this data structure uses large, contiguous blocks of memory
 // to store names and values. Lookups may be performed with StringPiece keys,
 // and values are returned as StringPieces (via StringPieceProxy, below).
 // Value StringPieces are valid as long as the SpdyHeaderBlock exists; allocated
 // memory is never freed until SpdyHeaderBlock's destruction.
 //
 // This implementation does not make much of an effort to minimize wasted space.
 // It's expected that keys are rarely deleted from a SpdyHeaderBlock.
 class NET_EXPORT SpdyHeaderBlock {
  private:
-  using MapType = linked_hash_map<base::StringPiece, base::StringPiece>;
+  using MapType = linked_hash_map<base::StringPiece,
+                                  base::StringPiece,
+                                  base::StringPieceHash>;
   class Storage;
 
  public:
   using iterator = MapType::iterator;
   using const_iterator = MapType::const_iterator;
   using value_type = MapType::value_type;
   using reverse_iterator = MapType::reverse_iterator;
 
   class StringPieceProxy;
 
@@ skipping 86 matching lines @@
 // to |headers|.  |event_param| must have been created by
 // SpdyHeaderBlockNetLogCallback.  On failure, returns false and clears
 // |headers|.
 NET_EXPORT bool SpdyHeaderBlockFromNetLogParam(
     const base::Value* event_param,
     SpdyHeaderBlock* headers);
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_HEADER_BLOCK_H_