Create wrapper scripts that set --output-directory

tools/android/wrapper_script.gni

+# 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.
+
+# Writes a script to root_out_dir/bin that passes --output-directory to the
+# wrapped script, in addition to forwarding arguments.
+template("wrapper_script") {
+  action(target_name) {
+    _name = get_path_info(invoker.target, "name")
+    _output = "$root_out_dir/bin/$_name"
+
+    script = "//build/android/gyp/create_tool_script.py"
+    outputs = [
+      _output,
+    ]
+
+    # The target isn't actually used by the script, but it's nice to have GN
+    # check that it exists.
+    inputs = [
+      invoker.target,
+    ]
+    args = [
+      "--output",
+      rebase_path(_output, root_build_dir),
+      "--target",
+      rebase_path(invoker.target, root_build_dir),
+      "--output-directory",
+      rebase_path(root_out_dir, root_build_dir),
+    ]
+  }
+}