Add copyright headers to remaining gyp files.

gyp/skia_lib.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.
 # The minimal set of static libraries for basic Skia functionality.
 
 {
   'variables': {
     'component_libs': [
       'core.gyp:core',
       'codec.gyp:codec',
       'effects.gyp:effects',
       'images.gyp:images',
       'opts.gyp:opts',
@@ skipping 43 matching lines @@
       ],
       'dependencies': [
         '<@(component_libs)',
       ],
       'export_dependent_settings': [
         '<@(component_libs)',
       ],
     },
   ],
 }