Move Android's build_output_dirs target to its own file.

build/build_output_dirs_android.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.
+{
+  'targets': [
+    {
+      # Target for creating common output build directories. Creating output
+      # dirs beforehand ensures that build scripts can assume these folders to
+      # exist and there are no race conditions resulting from build scripts
+      # trying to create these directories.
+      # The build/java.gypi target depends on this target.
+      'target_name': 'build_output_dirs',
+      'type': 'none',
+      'actions': [
+        {
+          'action_name': 'create_java_output_dirs',
+          'variables' : {
+          'output_dirs' : [
+            '<(PRODUCT_DIR)/apks',
+            '<(PRODUCT_DIR)/lib.java',
+            '<(PRODUCT_DIR)/test.lib.java',
+           ]
+          },
+          'inputs' : [],
+          'outputs': [
+            '<@(output_dirs)'
+          ],
+          'action': [
+            'mkdir',
+            '-p',
+            '<@(output_dirs)',
+          ],
+        },
+      ],
+    }, # build_output_dirs
+  ], # targets
+}