Move NDK gyp file from third_party/android_tools.

BUG=428426

Review URL: https://codereview.chromium.org/864323002

Cr-Original-Commit-Position: refs/heads/master@{#313269}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: dce75c43ab1c93e89cf8fb98a51949a8225a3816

android/cpufeatures.gypi

@@ -24,7 +24,7 @@
       },
     }, {
       'dependencies': [
-        '<(android_ndk_root)/android_tools_ndk.gyp:cpu_features',
+        '<(DEPTH)/build/android/ndk.gyp:cpu_features',
       ],
     }],
   ],

android/ndk.gyp

@@ -0,0 +1,20 @@
+# Copyright (c) 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.
+
+{
+  'targets': [
+    {
+      'target_name': 'cpu_features',
+      'type': 'static_library',
+      'direct_dependent_settings': {
+        'include_dirs': [
+          '<(android_ndk_root)/sources/android/cpufeatures',
+        ],
+      },
+      'sources': [
+        '<(android_ndk_root)/sources/android/cpufeatures/cpu-features.c',
+      ],
+    },
+  ],
+}