Put the syzygy targets behind a 'syzygy_optimize' flag.

build/all.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     # A hook that can be overridden in other repositories to add additional
     # compilation targets to 'All'. Only used on Android.
     'android_app_targets%': [],
   },
@@ skipping 218 matching lines @@
           'dependencies': [
             '../google_apis/gcm/gcm.gyp:*',
           ],
         }],
       ],
     }, # target_name: All
     {
       'target_name': 'All_syzygy',
       'type': 'none',
       'conditions': [
-        ['OS=="win" and fastbuild==0 and target_arch=="ia32"', {
+        ['OS=="win" and fastbuild==0 and target_arch=="ia32" and '
+            '(syzyasan==1 or syzygy_optimize==1)', {
           'dependencies': [
             '../chrome/installer/mini_installer_syzygy.gyp:*',
           ],
         }],
       ],
     }, # target_name: All_syzygy
     {
       # Note: Android uses android_builder_tests below.
       # TODO: Consider merging that with this target.
       'target_name': 'chromium_builder_tests',
@@ skipping 422 matching lines @@
             ['chromeos==0', {
               'dependencies': [
                 '../v8/src/d8.gyp:d8#host',
               ],
             }],
             ['internal_filter_fuzzer==1', {
               'dependencies': [
                 '../skia/tools/clusterfuzz-data/fuzzers/filter_fuzzer/filter_fuzzer.gyp:filter_fuzzer',
               ],
             }], # internal_filter_fuzzer
-            ['OS=="win" and fastbuild==0 and target_arch=="ia32"', {
+            ['OS=="win" and fastbuild==0 and target_arch=="ia32" and syzyasan==1', {
               'dependencies': [
                 '../chrome/chrome_syzygy.gyp:chrome_dll_syzygy',
                 '../content/content_shell_and_tests.gyp:content_shell_syzyasan',
               ],
               'conditions': [
                 ['chrome_multiple_dll==1', {
                   'dependencies': [
                     '../chrome/chrome_syzygy.gyp:chrome_child_dll_syzygy',
                   ],
                 }],
@@ skipping 550 matching lines @@
             # http://crbug.com/157234
             #'../chrome/chrome.gyp:sync_integration_tests_run',
             '../chrome/chrome.gyp:unit_tests_run',
             '../net/net.gyp:net_unittests_run',
           ],
         }, # target_name: chromium_swarm_tests
       ],
     }],
   ], # conditions
 }