Relocate ShapeResult's GlyphBuffer helpers to ShapeResultBuffer

third_party/WebKit/Source/platform/blink_platform.gypi

 {
   'includes': [
     'platform_generated.gypi',
   ],
   'variables': {
     'platform_files': [
       'AsyncFileSystemCallbacks.h',
       'CalculationValue.h',
       'CheckedInt.h',
       'Clock.cpp',
@@ skipping 420 matching lines @@
       'fonts/shaping/CachingWordShaper.h',
       'fonts/shaping/HarfBuzzFace.cpp',
       'fonts/shaping/HarfBuzzFace.h',
       'fonts/shaping/HarfBuzzShaper.cpp',
       'fonts/shaping/HarfBuzzShaper.h',
       'fonts/shaping/RunSegmenter.h',
       'fonts/shaping/RunSegmenter.cpp',
       'fonts/shaping/ShapeCache.h',
       'fonts/shaping/ShapeResult.cpp',
       'fonts/shaping/ShapeResult.h',
+      'fonts/shaping/ShapeResultBuffer.cpp',
+      'fonts/shaping/ShapeResultBuffer.h',
       'fonts/shaping/ShapeResultInlineHeaders.h',
       'fonts/shaping/ShapeResultTestInfo.cpp',
       'fonts/shaping/ShapeResultTestInfo.h',
       'fonts/shaping/Shaper.cpp',
       'fonts/shaping/Shaper.h',
       'fonts/shaping/SimpleShaper.cpp',
       'fonts/shaping/SimpleShaper.h',
       'fonts/skia/FontCacheSkia.cpp',
       'fonts/win/FontCacheSkiaWin.cpp',
       'fonts/win/FontFallbackWin.cpp',
@@ skipping 674 matching lines @@
       ['OS!="mac"',
         {
           'platform_test_files': [
             'scroll/ScrollAnimatorTest.cpp',
           ],
         }
       ],
     ],
   },
 }