Add copyright headers to remaining gyp files.

gyp/pathops_skpclip.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 pathops skp clip test.
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
     {
       'target_name': 'pathops_skpclip',
       'type': 'executable',
       'include_dirs': [
@@ skipping 26 matching lines @@
         }],
         [ 'skia_gpu == 1', {
           'include_dirs': [
             '../src/gpu',
           ],
         }],
       ],
     },
   ],
 }