Revert of Move gn _run target generation into test().

media/BUILD.gn

Index: media/BUILD.gn
diff --git a/media/BUILD.gn b/media/BUILD.gn
index b4d05e5e9e5039a2b9d4c4b0b568591485091e69..e8c0a87a91aa1188914a0313d2c2c243cbe904a9 100644
--- a/media/BUILD.gn
+++ b/media/BUILD.gn
@@ -610,6 +610,15 @@
   }
 }
 
+# TODO(GYP): Delete this after we've converted everything to GN.
+# The _run targets exist only for compatibility w/ GYP.
+group("media_unittests_run") {
+  testonly = true
+  deps = [
+    ":media_unittests",
+  ]
+}
+
 test("media_unittests") {
   sources = [
     "capture/content/animated_content_sampler_unittest.cc",
@@ -830,6 +839,15 @@
   }
 }
 
+# TODO(GYP): Delete this after we've converted everything to GN.
+# The _run targets exist only for compatibility w/ GYP.
+group("audio_unittests_run") {
+  testonly = true
+  deps = [
+    ":audio_unittests",
+  ]
+}
+
 # For running the subset of media_unittests that might require audio hardware
 # separately on GPU bots. media_unittests includes these too.
 test("audio_unittests") {