Brave crashes at startup with segfault when --disable-sync flag is used

[AndriusA]

Description

On MacOS Brave crashes at startup when launched with --disable-sync flag. Used by various automation tools by default, e.g. puppeteer, lighthouse.

Steps to Reproduce

  /Applications/Brave\ Browser.app/Contents/MacOS/Brave\ Browser \
        --user-data-dir=~/Downloads/brave-profile-test-stable \
        --disable-sync \
        --enable-logging=stderr \
        about:blank

Actual result:

[79514:775:0206/191904.104627:WARNING:account_consistency_mode_manager.cc(288)] Desktop Identity Consistency cannot be enabled as no OAuth client ID and client secret have been configured.
[79514:775:0206/191904.155696:WARNING:push_messaging_service_factory.cc(37)] PushMessagingService could not be built because InstanceID is unexpectedly disabled
[79514:775:0206/191904.158866:INFO:ads_service_impl.cc(1218)] Migrating ads preferences
[79514:775:0206/191904.158903:INFO:ads_service_impl.cc(1244)] Ads preferences are up to date on version 6
[79514:775:0206/191904.238665:WARNING:push_messaging_service_factory.cc(37)] PushMessagingService could not be built because InstanceID is unexpectedly disabled
[79514:775:0206/191904.247677:WARNING:push_messaging_service_factory.cc(37)] PushMessagingService could not be built because InstanceID is unexpectedly disabled
[79514:775:0206/191904.702724:WARNING:push_messaging_service_factory.cc(37)] PushMessagingService could not be built because InstanceID is unexpectedly disabled
[79514:775:0206/191904.703542:WARNING:push_messaging_service_factory.cc(37)] PushMessagingService could not be built because InstanceID is unexpectedly disabled
[0206/191904.715456:WARNING:process_memory_mac.cc(93)] mach_vm_read(0x7ffee2fd6000, 0x2000): (os/kern) invalid address (1)
[0206/191904.829352:WARNING:system_snapshot_mac.cc(42)] sysctlbyname kern.nx: No such file or directory (2)
[0206/191904.841744:WARNING:crash_report_exception_handler.cc(239)] UniversalExceptionRaise: (os/kern) failure (5)
[79524:775:0206/191904.848829:ERROR:child_thread_impl.cc(227)] Invalid PlatformChannel receive right
[0206/191904.850852:WARNING:process_memory_mac.cc(93)] mach_vm_read(0x7ffee899f000, 0x2000): (os/kern) invalid address (1)
[1]    79514 segmentation fault  /Applications/Brave\ Browser.app/Contents/MacOS/Brave\ Browser --disable-sync

Expected result:

Startup

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	1.6.7 Chromium: 80.0.3987.87 (Official Build) nightly (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	macOS Version 10.15.3 (Build 19D76)

As well as

Brave	1.2.43 Chromium: 79.0.3945.130 (Official Build) (64-bit)
Revision	e22de67c28798d98833a7137c0e22876237fc40a-refs/branch-heads/3945@{#1047}
OS	macOS Version 10.15.3 (Build 19D76)

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? not tried
• Can you reproduce this issue with the dev channel? not tried
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? N/A
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

[darkdh]

https://stats.brave.com/dashboard#crash/5e3c6bbf03639400693f3d23

[srirambv]

Verification passed on

Brave	1.3.115 Chromium: 80.0.3987.87 (Official Build) (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	Linux

• Verified no crash when running brave with --disable-sync
• Verified no Sync component shown in brave://inspect/#extensions
• Verified console doesn't show any crash reports
• Verified Sync is completely disabled in menu
• Verified visiting brave://sync shows invalid page error

Verification passed on

Brave	1.3.115 Chromium: 80.0.3987.87 (Official Build) (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified no crash when running brave with --disable-sync
• Verified no Sync component shown in brave://inspect/#extensions
• Verified console doesn't show any crash reports
• Verified Sync is completely disabled in the menu in all tabs (NT, PT and TOR tabs)
• Verified visiting brave://sync shows invalid page error
• Verified Extension: Brave Sync process isn't listed in task manager

Verified passed with

Brave	1.3.115 Chromium: 80.0.3987.87 (Official Build) (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	macOS Version 10.14.6 (Build 18G103)

• Verified test plan from Check result from ProfileSyncServiceFactory::GetForProfile  brave-core#4536 on a clean profile
• Verified test plan from Check result from ProfileSyncServiceFactory::GetForProfile  brave-core#4536 on a profile upgraded from 1.2.43 (profile that would have crashed)
• Verified test plan from Check result from ProfileSyncServiceFactory::GetForProfile  brave-core#4536 on a profile upgraded from 1.3.113 (crash profile)

Additionally, for each of the above:

• Confirmed no immediate crash when running brave with --disable-sync
• Confirmed no Sync component shown in brave://inspect/#extensions
• Confirmed console doesn't show any crash reports
• Confirmed Sync is completely disabled in the menu in all tabs (NT, PT and TOR tabs) - it is still displayed though, see sync still shows as disabled in hamburger menu #8158
• Confirmed visiting brave://sync shows invalid page error
• Confirmed Extension: Brave Sync process isn't listed in task manager
• Encountered Sync option still being displayed in brave://settings on side navigation menu, but section is removed from settings: sync still shows as an option in settings #8159