Use bundled freetype for tests.

samples/samples.gyp

 # Copyright 2014 PDFium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'target_defaults': {
     'defines' : [
       'PNG_PREFIX',
       'PNGPREFIX_H',
       'PNG_USE_READ_MACROS',
     ],
     'include_dirs': [
       '<(DEPTH)',
       '<(DEPTH)/v8',
       '<(DEPTH)/v8/include',
     ],
   },
   'targets': [
     {
       'target_name': 'pdfium_test',
       'type': 'executable',
       'dependencies': [
         'fx_lpng',
         '../pdfium.gyp:pdfium',
+        # Regardless of whether the library ships against system freetype,
+        # always link this binary against the bundled one for consistency
+        # of results across platforms.

[jam, 2015/07/30 17:18:03]

please copy this comment to the build.gn too so that we have it when the gyp
file is deleted

+        '../third_party/third_party.gyp:fx_freetype',
         '<(DEPTH)/v8/tools/gyp/v8.gyp:v8_libplatform',
       ],
       'sources': [
         'pdfium_test.cc',
         'image_diff_png.cc',
       ],
     },
     {
       'target_name': 'pdfium_diff',
       'type': 'executable',
@@ skipping 35 matching lines @@
         'fx_lpng/src/fx_pngset.c',
         'fx_lpng/src/fx_pngtrans.c',
         'fx_lpng/src/fx_pngwio.c',
         'fx_lpng/src/fx_pngwrite.c',
         'fx_lpng/src/fx_pngwtran.c',
         'fx_lpng/src/fx_pngwutil.c',
       ],
     },
   ],
 }