GN Windows component build fixes

media/midi/midi.gyp

Index: media/midi/midi.gyp
diff --git a/media/midi/midi.gyp b/media/midi/midi.gyp
index 554f1a977b2f206663a6c477944f511d4b9bb47b..0863bcb90318fb6f9f9a4e2429d71f43f93c78e4 100644
--- a/media/midi/midi.gyp
+++ b/media/midi/midi.gyp
@@ -36,12 +36,13 @@
         '../../base/base.gyp:base',
       ],
       'defines': [
-        'MEDIA_IMPLEMENTATION',
+        'MIDI_IMPLEMENTATION',
       ],
       'include_dirs': [
         '../..',
       ],
       'sources': [
+        'midi_export.h',
         'midi_manager.cc',
         'midi_manager.h',
         'midi_manager_android.cc',
@@ -98,6 +99,9 @@
             'midi_jni_registrar.cc',
             'midi_jni_registrar.h',
           ],
+          'defines': [
+            'EXPORT_USB_MIDI',
+          ],
         }],
         ['OS=="mac"', {
           'link_settings': {
@@ -124,9 +128,6 @@
         '../../base/base.gyp:run_all_unittests',
         '../../testing/gtest.gyp:gtest',
       ],
-      'defines': [
-        'MEDIA_IMPLEMENTATION',
-      ],
       'include_dirs': [
         '../..',
       ],