The macOS V2 Sandbox requires Chrome to allow access to notification_center:

(allow ipc-posix-shm-read-data
  (ipc-posix-name "apple.shm.notification_center"))

(allow mach-lookup
  (global-name "com.apple.system.notification_center"))

The reason for this is that QuickLookUI.framework opens a connection to notification_center in a static initializer. See the stack trace below.

It would be better to block the service, but that requires Apple to get rid of the initializer or for Chrome to hack out all of CFPreferences by swizzling it away (per rsesek@).

Stack trace of the attempt to open the shm handle:

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	0x00007fffdeaf613e __shm_open + 10
1   libsystem_notify.dylib        	0x00007fffdebd04fc notify_register_check + 535
2   libsystem_info.dylib          	0x00007fffdeab3155 __si_module_static_ds_block_invoke + 109
3   libdispatch.dylib             	0x00007fffde9918fc _dispatch_client_callout + 8
4   libdispatch.dylib             	0x00007fffde9918b9 dispatch_once_f + 38
5   libsystem_info.dylib          	0x00007fffdeab30e4 si_module_static_ds + 41
6   libsystem_info.dylib          	0x00007fffdeab2ba0 si_module_with_name + 230
7   libsystem_info.dylib          	0x00007fffdeab2fcb si_module_config_modules_for_category + 168
8   libsystem_info.dylib          	0x00007fffdeab2c67 __si_module_static_search_block_invoke + 83
9   libdispatch.dylib             	0x00007fffde9918fc _dispatch_client_callout + 8
10  libdispatch.dylib             	0x00007fffde9918b9 dispatch_once_f + 38
11  libsystem_info.dylib          	0x00007fffdeab2c11 si_module_static_search + 56
12  libsystem_info.dylib          	0x00007fffdeab2ba0 si_module_with_name + 230
13  libsystem_info.dylib          	0x00007fffdeab2a82 getpwuid + 32
14  com.apple.CoreFoundation      	0x00007fffc8db3cd8 _CFCopyHomeDirURLForUser + 152
15  com.apple.CoreFoundation      	0x00007fffc8edfa99 __96-[_CFXPreferences(SourceAdditions) withSourceForIdentifier:user:byHost:container:cloud:perform:]_block_invoke.211 + 265
16  com.apple.CoreFoundation      	0x00007fffc8ee001f -[_CFXPreferences(SourceAdditions) withSources:] + 79
17  com.apple.CoreFoundation      	0x00007fffc8edf7a1 -[_CFXPreferences(SourceAdditions) withSourceForIdentifier:user:byHost:container:cloud:perform:] + 817
18  com.apple.CoreFoundation      	0x00007fffc8db3a89 -[CFPrefsSearchListSource addSourceForIdentifier:user:byHost:container:] + 105
19  com.apple.CoreFoundation      	0x00007fffc8f2dadd __108-[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:]_block_invoke.256 + 445
20  com.apple.CoreFoundation      	0x00007fffc8f2ed8f -[_CFXPreferences(SearchListAdditions) withSearchLists:] + 79
21  com.apple.CoreFoundation      	0x00007fffc8f2d873 __108-[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:]_block_invoke + 259
22  com.apple.CoreFoundation      	0x00007fffc8f2d709 -[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:] + 345
23  com.apple.CoreFoundation      	0x00007fffc8f5a246 -[_CFXPreferences copyAppValueForKey:identifier:container:configurationURL:] + 310
24  com.apple.CoreFoundation      	0x00007fffc8dad634 _CFPreferencesGetAppBooleanValueWithContainer + 68
25  com.apple.QuickLookFramework  	0x00007fffceee02ca _QLAppPreferencesBooleanValueForKey + 50
26  com.apple.QuickLookUIFramework	0x00007fffcec37af9 _GLOBAL__sub_I_InterpolationUtils.mm + 18
27  dyld                          	0x000000010bb9ba1b ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) + 385
28  dyld                          	0x000000010bb9bc1e ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) + 40
29  dyld                          	0x000000010bb974aa ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 338
30  dyld                          	0x000000010bb97441 ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 233
31  dyld                          	0x000000010bb97441 ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 233
32  dyld                          	0x000000010bb97441 ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 233
33  dyld                          	0x000000010bb97441 ImageLoader::recursiveInitialization(ImageLoader::LinkContext const&, unsigned int, char const*, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 233
34  dyld                          	0x000000010bb96524 ImageLoader::processInitializers(ImageLoader::LinkContext const&, unsigned int, ImageLoader::InitializerTimingList&, ImageLoader::UninitedUpwards&) + 138
35  dyld                          	0x000000010bb965b9 ImageLoader::runInitializers(ImageLoader::LinkContext const&, ImageLoader::InitializerTimingList&) + 75
36  dyld                          	0x000000010bb8b7cd dyld::runInitializers(ImageLoader*) + 87
37  dyld                          	0x000000010bb933ec dlopen + 556
38  libdyld.dylib                 	0x00007fffde9c4832 dlopen + 59
39  org.chromium.Chromium.helper  	0x00000001003e73f9 main + 1609 (chrome_exe_main_mac.cc:152)
40  libdyld.dylib                 	0x00007fffde9c7235 start + 1