device: Restructure the layout of gyp files.

device/usb/usb.gyp

+# Copyright (c) 2012 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.
+
+{
+  'variables': {
+    'chromium_code': 1,
+  },
+  'targets': [
+    {
+      'target_name': 'usb',
+      'type': 'static_library',
+      'include_dirs': [
+        '../..',
+      ],
+      'sources': [
+        'usb_ids.cc',
+        'usb_ids.h',
+      ],
+      'actions': [
+        {
+          'action_name': 'generate_usb_ids',
+          'variables': {
+            'usb_ids_path%': '<(DEPTH)/third_party/usb_ids/usb.ids',
+            'usb_ids_py_path': '<(DEPTH)/tools/usb_ids/usb_ids.py',
+          },
+          'inputs': [
+            '<(usb_ids_path)',
+            '<(usb_ids_py_path)',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/device/usb/usb_ids_gen.cc',
+          ],
+          'action': [
+            'python',
+            '<(usb_ids_py_path)',
+            '-i', '<(usb_ids_path)',
+            '-o', '<@(_outputs)',
+          ],
+          'process_outputs_as_sources': 1,
+        },
+      ],
+    },
+  ],
+}