Move base::FreeDeleter into its own header.

base/BUILD.gn

 # 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 439 matching lines @@
     "md5.cc",
     "md5.h",
     "memory/aligned_memory.cc",
     "memory/aligned_memory.h",
     "memory/discardable_memory.cc",
     "memory/discardable_memory.h",
     "memory/discardable_memory_allocator.cc",
     "memory/discardable_memory_allocator.h",
     "memory/discardable_shared_memory.cc",
     "memory/discardable_shared_memory.h",
+    "memory/free_deleter.h",
     "memory/linked_ptr.h",
     "memory/manual_constructor.h",
     "memory/memory_pressure_listener.cc",
     "memory/memory_pressure_listener.h",
     "memory/memory_pressure_monitor.cc",
     "memory/memory_pressure_monitor.h",
     "memory/memory_pressure_monitor_chromeos.cc",
     "memory/memory_pressure_monitor_chromeos.h",
     "memory/memory_pressure_monitor_mac.cc",
     "memory/memory_pressure_monitor_mac.h",
@@ skipping 1850 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }