Stop filtering out the 'gears' SConscript on linux and mac.

SConscript.main

 # 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.
 
 import os
 import shutil
 import sys
 
 
 if sys.platform == 'win32':
@@ skipping 434 matching lines @@
     _PERL_INCLUDE_FLAGS = ('${_concat(PERL_INCLUDE_FLAG, '
                            'PERL_INCLUDE_PATH, '
                            'PERL_INCLUDE_SUFFIX,'
                            '__env__, RDirs, TARGET, SOURCE)}'),
 )
 
 linux_env.FilterOut(
     BUILD_SCONSCRIPTS = [
         '$BSPATCH_DIR/bspatch.scons',
         '$BSDIFF_DIR/bsdiff.scons',
-        '$GEARS_DIR/SConscript',
         '$GOOGLE_UPDATE_DIR/SConscript',
         '$RLZ_DIR/SConscript',
         '$SANDBOX_DIR/sandbox.scons',
     ],
 )
 
 linux_env.Append(
     # We need rt for clock_gettime.
     LIBS = ['rt'],
 
@@ skipping 75 matching lines @@
     CXX = 'g++-4.2',
     LINK = '$CXX',
 )
 
 mac_env.FilterOut(
     BUILD_SCONSCRIPTS = [
         '$BREAKPAD_DIR/SConscript',
         '$BSDIFF_DIR/bsdiff.scons',
         '$BSPATCH_DIR/bspatch.scons',
         '$CHROME_DIR/chrome.scons',
-        '$GEARS_DIR/SConscript',
         '$GOOGLE_UPDATE_DIR/SConscript',
         '$LIBJPEG_DIR/libjpeg.scons',
         '$LIBXML_DIR/libxml.scons',
         '$LIBXSLT_DIR/libxslt.scons',
         '$RLZ_DIR/SConscript',
         '$SANDBOX_DIR/sandbox.scons',
         '$WEBKIT_DIR/SConscript',
         'build/SConscript.v8',
     ],
 )
@@ skipping 157 matching lines @@
         'all_libraries',
         'all_languages',
         'all_programs',
         'all_test_programs',
     ], projects = [p],
     COMPONENT_VS_PROJECT_SCRIPT_PATH=(
         'cd $$(ProjectDir)/$VS_PROJECT_TO_MAIN_DIR && hammer.bat'),
 )
 
 # -------------------------------------------------------------------------