Reland: Web MIDI: split build rules for media/midi

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 1f7e756bc84d8f5be1a82d0176230d54f6bba841..a2c376a3247022831faf1c62e120706ad0447d54 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -65,6 +65,7 @@ group("gn_all") {
     "//mandoline",
     "//media:media_unittests",
     "//media/cast:cast_unittests",
+    "//media/midi:midi_unittests",
     "//mojo",
     "//mojo/application",
     "//mojo/common:mojo_common_unittests",
@@ -721,8 +722,9 @@ if (is_linux) {
       "//ipc:ipc_tests",  # PASSES 2/25/2015
       "//ipc/mojo:ipc_mojo_unittests",  # PASSES 2/25/2015
       "//jingle:jingle_unittests",  # PASSES 2/25/2015
-      "//media/cast:cast_unittests",  # PASSES 2/25/2015
       "//media:media_unittests",  # PASSES 3/3/2015
+      "//media/cast:cast_unittests",  # PASSES 2/25/2015
+      "//media/midi:midi_unittests",  # PASSES 4/10/2015
       "//mojo/common:mojo_common_unittests",  # PASSES 2/25/2015
       "//net:net_unittests",  # PASSES 2/25/2015
       "//ppapi:ppapi_unittests",  # PASSES 2/26/2015