Enable ASSERT when DCHECK_ALWAYS_ON is defined.

Source/wtf/wtf.gyp

 # Copyright (C) 2012 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 10 matching lines @@
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 {
   'includes': [
     '../build/win/precompile.gypi',
+    '../build/defines_from_chromium.gypi',
     '../build/features.gypi',
     'wtf.gypi',
   ],
   'conditions': [
     ['gcc_version>=46', {
       'target_defaults': {
         # Disable warnings about c++0x compatibility, as some names (such as nullptr) conflict
         # with upcoming c++0x types.
         'cflags_cc': ['-Wno-c++0x-compat'],
       },
@@ skipping 112 matching lines @@
             ['exclude', 'CF\\.cpp$'],
             ['exclude', 'Mac\\.mm$'],
             # mac is the only OS that uses WebKit's copy of TCMalloc.
             ['exclude', 'TC.*\\.(cpp|h)$'],
           ],
         }],
       ],
     },
   ]
 }