Add copyright headers to remaining gyp files.

gyp/effects.gypi

+# Copyright 2015 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
 # Include this gypi to include all 'effects' files
 # The parent gyp/gypi file must define:
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi.
 #
 {
   'sources': [
     '<(skia_src_path)/effects/Sk1DPathEffect.cpp',
@@ skipping 100 matching lines @@
     '<(skia_include_path)/effects/SkPerlinNoiseShader.h',
     '<(skia_include_path)/effects/SkPixelXorXfermode.h',
     '<(skia_include_path)/effects/SkRectShaderImageFilter.h',
     '<(skia_include_path)/effects/SkTableColorFilter.h',
     '<(skia_include_path)/effects/SkTableMaskFilter.h',
     '<(skia_include_path)/effects/SkTileImageFilter.h',
     '<(skia_include_path)/effects/SkTransparentShader.h',
     '<(skia_include_path)/effects/SkMagnifierImageFilter.h',
   ],
 }