Introduce object visitor to estimate the size of a native context.

tools/gyp/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 596 matching lines @@
         '../../src/compiler/typer.cc',
         '../../src/compiler/typer.h',
         '../../src/compiler/value-numbering-reducer.cc',
         '../../src/compiler/value-numbering-reducer.h',
         '../../src/compiler/verifier.cc',
         '../../src/compiler/verifier.h',
         '../../src/compiler/zone-pool.cc',
         '../../src/compiler/zone-pool.h',
         '../../src/compiler.cc',
         '../../src/compiler.h',
+        '../../src/context-measure.cc',
+        '../../src/context-measure.h',
         '../../src/contexts.cc',
         '../../src/contexts.h',
         '../../src/conversions-inl.h',
         '../../src/conversions.cc',
         '../../src/conversions.h',
         '../../src/counters.cc',
         '../../src/counters.h',
         '../../src/cpu-profiler-inl.h',
         '../../src/cpu-profiler.cc',
         '../../src/cpu-profiler.h',
@@ skipping 1360 matching lines @@
         }],
         ['want_separate_host_toolset==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }