Don't try to compile .mk files when building shared libraries...

site_scons/site_tools/chromium_builders.py

 # Copyright (c) 2006-2008 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.
 
 """
 Tool module for adding, to a construction environment, Chromium-specific
 wrappers around SCons builders.  This gives us a central place for any
 customization we need to make to the different things we build.
 """
 
@@ skipping 149 matching lines @@
 non_compilable_suffixes = {
     'LINUX' : set([
         '.bdic',
         '.css',
         '.dat',
         '.gperf',
         '.h',
         '.html',
         '.hxx',
         '.idl',
+        '.mk',
         '.js',
         '.rc',
     ]),
     'WINDOWS' : set([
         '.h',
         '.dat',
         '.idl',
     ]),
 }
 
@@ skipping 80 matching lines @@
   # Add the grit tool to the base environment because we use this a lot.
   sys.path.append(env.Dir('$SRC_DIR/tools/grit').abspath)
   env.Tool('scons', toolpath=[env.Dir('$SRC_DIR/tools/grit/grit')])
 
   # Add the repack python script tool that we use in multiple places.
   sys.path.append(env.Dir('$SRC_DIR/tools/data_pack').abspath)
   env.Tool('scons', toolpath=[env.Dir('$SRC_DIR/tools/data_pack/')])
 
 def exists(env):
   return True