Have /src files use header directly.

gyp/views.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.
 # Views is the Skia windowing toolkit.
 # It provides:
 #  * A portable means of creating native windows.
 #  * Events.
 #  * Basic widgets and controls.
 
 {
   'targets': [
     {
       'target_name': 'views',
       'product_name': 'skia_views',
       'type': 'static_library',
       'standalone_static_library': 1,
       'dependencies': [
         'skia_lib.gyp:skia_lib',
         'xml.gyp:xml',
       ],
       'include_dirs': [
+        '../include/private',
         '../include/views',
         '../include/views/unix',
         '../src/gpu',
       ],
       'sources': [
         '../include/views/SkApplication.h',
         '../include/views/SkBGViewArtist.h',
         '../include/views/SkEvent.h',
         '../include/views/SkEventSink.h',
         '../include/views/SkKey.h',
@@ skipping 112 matching lines @@
         'include_dirs': [
           '../include/views',
         ],
       },
       'export_dependent_settings': [
         'xml.gyp:xml',
       ],
     },
   ],
 }