Switch libvpx from static_library to none

libvpx.gyp

Index: libvpx.gyp
diff --git a/libvpx.gyp b/libvpx.gyp
index 725d9a92f2b962370b56174379b6334eec1bdf53..5ee612ec297faa5589da56a9817d76a4b194aa06 100644
--- a/libvpx.gyp
+++ b/libvpx.gyp
@@ -7,15 +7,13 @@
       # This libvpx target contains both encoder and decoder.
       # Encoder is configured to be realtime only.
       'target_name': 'libvpx',
-      'type': 'static_library',
+      'type': 'none',
       'dependencies': [
         '<(DEPTH)/third_party/libvpx_new/libvpx.gyp:libvpx_new'
       ],
-      'direct_dependent_settings': {
-        'include_dirs': [
-          '<(DEPTH)/third_party/libvpx_new/source/libvpx',
-        ],
-      },
+      'export_dependent_settings': [
+        '<(DEPTH)/third_party/libvpx_new/libvpx.gyp:libvpx_new'
+      ],
     },
   ],
 }