Extract //device/usb mocks so that they can be shared.

device/BUILD.gn

 # Copyright 2015 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("//testing/test.gni")
 
 if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
 }
@@ skipping 81 matching lines @@
     sources += [
       "test/usb_test_gadget_impl.cc",
       "usb/usb_context_unittest.cc",
       "usb/usb_device_filter_unittest.cc",
       "usb/usb_device_handle_unittest.cc",
       "usb/usb_ids_unittest.cc",
       "usb/usb_service_unittest.cc",
     ]
     deps += [
       "//device/usb",
+      "//device/usb:mocks",
       "//third_party/libusb",
     ]
   }
 
   if (is_chromeos) {
     configs += [ "//build/config/linux:dbus" ]
 
     deps += [
       "//chromeos",
       "//chromeos:test_support",
@@ skipping 11 matching lines @@
 
     # In the OSX 10.10 SDK, CoreBluetooth became a top level framework.
     # Previously, it was nested in IOBluetooth. In order for Chrome to run on
     # OSes older than OSX 10.10, the top level CoreBluetooth framework must be
     # weakly linked.
     if (mac_sdk_version == "10.10") {
       ldflags = [ "-weak_framework CoreBluetooth" ]
     }
   }
 }