Flag to re-enable sync

[jsecretan]

Description

As we temporarily have Brave Sync disabled, we need to provide a flag that we can use to re-enable for internal testing.

Brave version (brave://version info)

1.3.115

Version/Channel Information:

Release

[Gby56]

oh so Brave Sync has been disabled for now ? Was it announced anywhere ?
I was trying to test this out but it kept crashing Brave after staying too long on "looking for devices"
Then I updated, and brave://sync isn't working, but the "Sync" link in the settings page is still there fyi

[NejcZdovc]

@Gby56 you can read more about sync begin disabled here https://community.brave.com/t/brave-sync-temporarily-disabled-on-desktop/106837

[GeetaSarvadnya]

Verification passed on

Brave	1.3.116 Chromium: 80.0.3987.106 (Official Build) (64-bit)
Revision	f68069574609230cf9b635cd784cfb1bf81bb53a-refs/branch-heads/3987@{#882}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified the test plan from Add Brave Sync flag to control whether to append --disable-sync brave-core#4592
• Verified --disable-sync flag is appended in the command line when the sync is Disabled in chrome://flags/#brave-sync
  
• Verified --disable-sync flag is NOT appended in the command line when the sync is Enabled in chrome://flags/#brave-sync
  
• Verified --disable-sync flag is appended in the command line when the sync is set to Default in chrome://flags/#brave-sync
  
• Upgraded from 1.3.113 to 1.3.116 and verified that sync is disabled by default and sync can be enabled via chrome://flags/#brave-sync
• Upgraded from 1.3.115 to 1.3.116 and verified that sync is disabled by default and sync can be enabled via chrome://flags/#brave-sync
• Create sync chain in 1.3.113 and upgrade to 1.3.116 and verified that sync is not enabled and the message This site can’t be reached is displayed in an upgraded profile
• Verified that sync is working as expected in an upgraded and clean profile 1.3.116 when the sync is enabled via chrome://flags/#brave-sync
• Verified that no errors in the console logs when the sync is enabled

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Verification passed on

Brave	1.3.116 Chromium: 80.0.3987.106 (Official Build) (64-bit)
Revision	f68069574609230cf9b635cd784cfb1bf81bb53a-refs/branch-heads/3987@{#882}
OS	Linux

• Verified test plan from Add Brave Sync flag to control whether to append --disable-sync brave-core#4592
• Verified --disable-sync argument is passed when sync flag is default/disabled
  
• Verified --disable-sync is not in command line args when Sync flag is enabled
  
• Verified creating a sync chain on 1.2.43 and then upgrading to 1.3.116 passed --disable-sync argument and there was no sync option
• Verified enabling flag after upgrading from 1.2.43 to 1.3.116, retained the same sync chain
• Verified bookmarks sync on upgrade with the same sync chain
• Verified upgrading from 1.3.113 to 1.3.116 sync is disabled by default and can be enabled via flag

---

Verified passed with

Brave	1.3.116 Chromium: 80.0.3987.106 (Official Build) (64-bit)
Revision	f68069574609230cf9b635cd784cfb1bf81bb53a-refs/branch-heads/3987@{#882}
OS	macOS Version 10.14.6 (Build 18G3020)

• Verified the test plan from Add Brave Sync flag to control whether to append --disable-sync brave-core#4592

When Flag is set to Disabled or Default, --disable-sync is displayed on brave://version:

When Flag is set to Enabled, --disable-sync is not displayed on brave://version:

• Upgraded from 1.3.115 to 1.3.116 and verified that sync is disabled by default and sync can be enabled via brave://flags/#brave-sync
• Create sync chain in 1.3.113 and upgrade to 1.3.116 and verified that sync is not enabled and the message This site can’t be reached is displayed in an upgraded profile
• Verified that sync is working as expected in an upgraded and clean profile 1.3.116 when the sync is enabled via brave://flags/#brave-sync