Revert r229671 "aura: Allow creating content_shell without views."

http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20Builder%20%28deps%29/builds/74852/steps/compile/logs/stdio

git-svn-id: http://src.chromium.org/svn/trunk/src/build@229683 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

build_config.h

@@ -31,7 +31,7 @@
 #elif defined(__linux__)
 #define OS_LINUX 1
 // Use TOOLKIT_GTK on linux if TOOLKIT_VIEWS isn't defined.
-#if !defined(TOOLKIT_VIEWS) && defined(USE_X11) && !defined(USE_AURA)
+#if !defined(TOOLKIT_VIEWS) && defined(USE_X11)
 #define TOOLKIT_GTK
 #endif
 #if defined(__GLIBC__) && !defined(__UCLIBC__)