mac: Remove some 10.6-SDK-only sandbox code.

sandbox/mac/sandbox_mac.gypi

Index: sandbox/mac/sandbox_mac.gypi
diff --git a/sandbox/mac/sandbox_mac.gypi b/sandbox/mac/sandbox_mac.gypi
index 91ad20bac7aaaf4163f90461ec7cc2608bd4e1fb..13aa4039c9f1ead3e123ed22598e7189c0d216df 100644
--- a/sandbox/mac/sandbox_mac.gypi
+++ b/sandbox/mac/sandbox_mac.gypi
@@ -21,7 +21,6 @@
         'policy.h',
         'pre_exec_delegate.cc',
         'pre_exec_delegate.h',
-        'xpc.cc',
         'xpc.h',
         'xpc_message_server.cc',
         'xpc_message_server.h',
@@ -41,52 +40,6 @@
           '$(SDKROOT)/usr/lib/libbsm.dylib',
         ],
       },
-      'conditions': [
-        # When the build SDK is 10.6, generate a dynamic stub loader. When the
-        # SDK is higher, then libxpc.dylib will be loaded automatically as part
-        # of libSystem, and only forward declarations of private symbols are
-        # necessary.
-        ['mac_sdk == "10.6"', {
-          'actions': [
-            {
-              'variables': {
-                'generate_stubs_script': '../tools/generate_stubs/generate_stubs.py',
-                'generate_stubs_header_path': 'xpc_stubs_header.fragment',
-                'generate_stubs_sig_public_path': 'xpc_stubs.sig',
-                'generate_stubs_sig_private_path': 'xpc_private_stubs.sig',
-                'generate_stubs_project': 'sandbox/mac',
-                'generate_stubs_output_stem': 'xpc_stubs',
-              },
-              'action_name': 'generate_stubs',
-              'inputs': [
-                '<(generate_stubs_script)',
-                '<(generate_stubs_header_path)',
-                '<(generate_stubs_sig_public_path)',
-                '<(generate_stubs_sig_private_path)',
-              ],
-              'outputs': [
-                '<(INTERMEDIATE_DIR)/<(generate_stubs_output_stem).cc',
-                '<(SHARED_INTERMEDIATE_DIR)/<(generate_stubs_project)/<(generate_stubs_output_stem).h',
-              ],
-              'action': [
-                'python',
-                '<(generate_stubs_script)',
-                '-i', '<(INTERMEDIATE_DIR)',
-                '-o', '<(SHARED_INTERMEDIATE_DIR)/<(generate_stubs_project)',
-                '-t', 'posix_stubs',
-                '-e', '<(generate_stubs_header_path)',
-                '-s', '<(generate_stubs_output_stem)',
-                '-p', '<(generate_stubs_project)',
-                '-x', 'SANDBOX_EXPORT',
-                '<(generate_stubs_sig_public_path)',
-                '<(generate_stubs_sig_private_path)',
-              ],
-              'process_outputs_as_sources': 1,
-              'message': 'Generating XPC stubs for 10.6 compatability.',
-            },
-          ],
-        }],
-      ],
     },
     {
       'target_name': 'sandbox_mac_unittests',