Remove the _cpp_sources target from mojom.

content/browser/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
 import("//third_party/WebKit/public/public_features.gni")
@@ skipping 75 matching lines @@
     "//gpu/command_buffer/client:gles2_implementation",
     "//gpu/command_buffer/client:gles2_interface",
     "//gpu/ipc/host",
     "//ipc",
     "//ipc:mojom",
     "//media",
     "//media/capture",
     "//media/capture/mojo:image_capture",
     "//media/gpu/ipc/client",
     "//media/midi",
-    "//media/midi:mojo_cpp_sources",
+    "//media/midi:mojo",
     "//media/mojo/interfaces",
     "//mojo/common",
     "//mojo/edk/system",
     "//mojo/public/cpp/bindings",
     "//mojo/public/js",
     "//net",
     "//net:extras",
     "//net:http_server",
     "//ppapi/features",
     "//printing/features",
@@ skipping 1885 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }