Include paths for dependent projects

libvpx.gyp

Index: libvpx.gyp
diff --git a/libvpx.gyp b/libvpx.gyp
index be969e228285bdb835215e77140cfc26e6846cf2..b975e6cced229fe0899832a0e09aaf8a02e4e16d 100644
--- a/libvpx.gyp
+++ b/libvpx.gyp
@@ -4,11 +4,18 @@
 {
   'targets': [
     {
+      # This libvpx target contains both encoder and decoder.
+      # Encoder is configured to be realtime only.
       'target_name': 'libvpx',
       'type': 'static_library',
       'dependencies': [
         '<(DEPTH)/third_party/libvpx_new/libvpx.gyp:libvpx_new'
       ]
+      'direct_dependent_settings': {
+        'include_dirs': [
+          '../libvpx_new/source/libvpx',
+        ],
+      },
     },
   ],
 }