GN: get echo-headers sources via exec_script

gyp/tools.gyp

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
     # GYP file to build various tools.
 #
 # To build on Linux:
 #  ./gyp_skia tools.gyp && make tools
 #
 {
@@ skipping 98 matching lines @@
             '../src/effects',
             '../src/effects/gradients',
             '../src/image',
             '../src/gpu',
             '../src/pdf',
             '../src/utils',
         ],
         'sources': [
             '../tools/monobench.cpp',
             '../bench/Benchmark.cpp',
-            '<!@(python find.py ../bench "*Bench.cpp")',
+            '<!@(python find.py "*Bench.cpp" ../bench)',
         ],
         'sources!': [
             '../bench/GMBench.cpp',
         ],
     },
     {
       'target_name': 'chrome_fuzz',
       'type': 'executable',
       'sources': [
         '../tools/chrome_fuzz.cpp',
@@ skipping 565 matching lines @@
               'pdf.gyp:pdf',
               'gputest.gyp:osmesa',
             ],
             'defines': [ 'FIDDLE_BUILD_TEST' ],
           },
         ],
       },
     ],
   ],
 }