OS(ANDROID) should not imply OS(LINUX)

Source/config.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2013 Apple Inc.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) 2010, 2011 Research In Motion Limited. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 31 matching lines @@
 #define USE(WTF_FEATURE) (defined WTF_USE_##WTF_FEATURE  && WTF_USE_##WTF_FEATURE)
 /* ENABLE() - turn on a specific feature of WebKit */
 #define ENABLE(WTF_FEATURE) (defined ENABLE_##WTF_FEATURE  && ENABLE_##WTF_FEATURE)
 
 /* ==== OS() - underlying operating system; only to be used for mandated low-level services like
    virtual memory, not to choose a GUI toolkit ==== */
 
 /* OS(ANDROID) - Android */
 #ifdef ANDROID
 #define WTF_OS_ANDROID 1
-#endif
-
 /* OS(MACOSX) - Any Darwin-based OS, including Mac OS X and iPhone OS */
-#ifdef __APPLE__
+#elif defined(__APPLE__)
 #define WTF_OS_MACOSX 1
-#endif
-
 /* OS(FREEBSD) - FreeBSD */
-#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
+#elif defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
 #define WTF_OS_FREEBSD 1
-#endif
-
 /* OS(LINUX) - Linux */
-#ifdef __linux__
+#elif defined(__linux__)
 #define WTF_OS_LINUX 1
-#endif
-
 /* OS(OPENBSD) - OpenBSD */
-#ifdef __OpenBSD__
+#elif defined(__OpenBSD__)
 #define WTF_OS_OPENBSD 1
-#endif
-
 /* OS(WIN) - Any version of Windows */
-#if defined(WIN32) || defined(_WIN32)
+#elif defined(WIN32) || defined(_WIN32)
 #define WTF_OS_WIN 1
 #endif
 
 /* OS(POSIX) - Any Unix-like system */
 #if OS(ANDROID)          \
     || OS(MACOSX)           \
     || OS(FREEBSD)          \
     || OS(LINUX)            \
     || OS(OPENBSD)          \
     || defined(unix)        \
@@ skipping 91 matching lines @@
 #define SKIP_STATIC_CONSTRUCTORS_ON_GCC 1
 #endif
 
 #ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS 1
 #endif
 
 #if OS(LINUX) || OS(ANDROID)
 #define WTF_USE_HARFBUZZ 1
 #endif