Replace uses of hash_map in //base

base/memory/shared_memory.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 BASE_MEMORY_SHARED_MEMORY_H_
 #define BASE_MEMORY_SHARED_MEMORY_H_
 
 #include <stddef.h>
 
 #include <string>
 
 #include "base/base_export.h"
+#include "base/hash.h"
 #include "base/macros.h"
 #include "base/memory/shared_memory_handle.h"
 #include "base/process/process_handle.h"
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <stdio.h>
 #include <sys/types.h>
 #include <semaphore.h>
 #include "base/file_descriptor_posix.h"
@@ skipping 290 matching lines @@
   void*              memory_;
   bool               read_only_;
   size_t             requested_size_;
 
   DISALLOW_COPY_AND_ASSIGN(SharedMemory);
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_SHARED_MEMORY_H_