Add generate_jni template

tools/gn/secondary/third_party/android_tools/BUILD.gn

Index: tools/gn/secondary/third_party/android_tools/BUILD.gn
diff --git a/tools/gn/secondary/third_party/android_tools/BUILD.gn b/tools/gn/secondary/third_party/android_tools/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..b5f6ebdddc569e5124825277aa7d083ffe07f237
--- /dev/null
+++ b/tools/gn/secondary/third_party/android_tools/BUILD.gn
@@ -0,0 +1,15 @@
+# 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.
+
+config("cpu_features_include") {
+  include_dirs = [ "ndk/sources/android/cpufeatures" ]
+}
+
+source_set("cpu_features") {
+  sources = [ "ndk/sources/android/cpufeatures/cpu-features.c" ]
+  direct_dependent_configs = [ ":cpu_features_include" ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+}