Remove //device/devices_app.

device/usb/mojo/BUILD.gn

Index: device/usb/mojo/BUILD.gn
diff --git a/device/usb/mojo/BUILD.gn b/device/usb/mojo/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..d48cf378718817670e2472c156044680259663f0
--- /dev/null
+++ b/device/usb/mojo/BUILD.gn
@@ -0,0 +1,24 @@
+# Copyright 2016 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.
+
+source_set("mojo") {
+  sources = [
+    "device_impl.cc",
+    "device_impl.h",
+    "device_manager_impl.cc",
+    "device_manager_impl.h",
+    "type_converters.cc",
+    "type_converters.h",
+  ]
+
+  deps = [
+    "//device/core",
+    "//device/usb",
+    "//device/usb/public/interfaces",
+    "//mojo/common",
+    "//mojo/public/cpp/bindings",
+    "//mojo/public/cpp/bindings:callback",
+    "//net",
+  ]
+}