media: Make media mojo services a component

Previously media mojo services are in multiple small source_sets. This
was okay when they are only depended by one target (i.e. content). But
now we have multiple targets depending on them. For example, content and
media/gpu both depend on cdm_services. This causes duplicate definition
of some global veriables, e.g. g_cdm_manager in mojo_cdm_service.cc.

[email protected]
BUG=610904
TEST=EME playback works.

Review-Url: https://codereview.chromium.org/1968833002
Cr-Commit-Position: refs/heads/master@{#394323}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 7c513a0..d8f9496 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -940,7 +940,7 @@
     ]
     deps += [ "//media/mojo/interfaces" ]
     if (mojo_media_host == "browser") {
-      deps += [ "//media/mojo/services:application_factory" ]
+      deps += [ "//media/mojo/services" ]
     }
   }