Reland of move v8_toolset_for_d8 flag

src/d8.gyp

 # Copyright 2012 the V8 project authors. 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 in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 # 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.
 
 {
   'variables': {
     'v8_code': 1,
     # Enable support for Intel VTune. Supported on ia32/x64 only
     'v8_enable_vtunejit%': 0,
     'v8_enable_i18n_support%': 1,
-    'v8_toolset_for_d8%': 'target',
   },
   'includes': ['../gypfiles/toolchain.gypi', '../gypfiles/features.gypi'],
   'targets': [
     {
       'target_name': 'd8',
       'type': 'executable',
       'dependencies': [
         'v8.gyp:v8',
         'v8.gyp:v8_libplatform',
       ],
       # Generated source files need this explicitly:
       'include_dirs+': [
         '..',
       ],
       'sources': [
         'd8.h',
         'd8.cc',
       ],
       'conditions': [
         [ 'want_separate_host_toolset==1', {
-          'toolsets': [ '<(v8_toolset_for_d8)', ],
+          'toolsets': [ 'target', ],
         }],
         ['(OS=="linux" or OS=="mac" or OS=="freebsd" or OS=="netbsd" \
            or OS=="openbsd" or OS=="solaris" or OS=="android" \
            or OS=="qnx" or OS=="aix")', {
              'sources': [ 'd8-posix.cc', ]
            }],
         [ 'OS=="win"', {
           'sources': [ 'd8-windows.cc', ]
         }],
         [ 'component!="shared_library"', {
@@ skipping 68 matching lines @@
             '../tools/js2c.py',
             '<@(_outputs)',
             'D8',
             '<@(js_files)'
           ],
         },
       ],
     },
   ],
   'conditions': [
-    ['test_isolation_mode != "noop" and v8_toolset_for_d8 == "target"', {
+    ['test_isolation_mode != "noop"', {
       'targets': [
         {
           'target_name': 'd8_run',
           'type': 'none',
           'dependencies': [
             'd8',
           ],
           'includes': [
             '../gypfiles/isolate.gypi',
           ],
           'sources': [
             'd8.isolate',
           ],
         },
       ],
     }],
   ],
 }