Move the android library loader from content to base

build/android/tests/multiple_proguards/src/dummy/NativeLibraries.java

+// 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.
+
+package org.chromium.base.library_loader;
+
+/**
+ * This is a complete dummy, required because base now requires a version of
+ * NativeLibraries to build, but doesn't include it in its jar file.
+ */
+public class NativeLibraries {
+    public static boolean USE_LINKER = false;
+    public static boolean ENABLE_LINKER_TESTS = false;
+    static final String[] LIBRARIES = {};
+    static String VERSION_NUMBER = "";
+}