Properly handle Qwant in private windows + tor windows

[bsclifton]

Test plan

1. Fresh install of Brave (new profile directory, etc)
2. Set region as France
3. Launch Brave- verify Qwant is default for:
   • regular tabs
   • private window tabs
   • private window tabs with Tor
4. Change default search engine to Bing
5. Verify Bing is used in:
   • regular tabs
   • private window tabs
6. Verify Qwant is used for private tabs
7. Verify that DDG logo/wording does NOT show in:
   • private window tabs
   • private window tabs with Tor
8. Repeat steps 3-7 with region as Germany
9. Clear profile; set region as your real location (United States, Canada, etc)
10. Launch Brave
11. Verify DDG logo/wording DOES show in
    • private window tabs
    • private window tabs with Tor
12. Verify DDG is used as the default search for private window tabs with Tor

Edited description

This is a follow up to #1632

This issue originally was match the behavior in Muon, but the intention is now to handle it how we want it (verified by @davidtemkin). As he noted in brave/brave-core#685 (comment):

DDG should never be promoted / shown / defaulted on in Qwant regions. In Qwant regions, we default to Qwant for search in all types of windows, including private and private/tor and do not promote DDG.

[simonhong]

Hmm, I'm a little bit confusing with newtab UX in private(with or w/o tor).
I found that there are two kinds of ddg version new tab - with or w/o ddg toggle button.
It would be helpful to me if I can know the exact UX scenario of newtab.
=> I found that DDG new tab with toggle button is only visible in private window(non-tor).

[bsclifton]

Notes in original issue above fixed after verifying intended behavior

[GeetaSarvadnya]

@bsclifton step 6: should it be 'Verify Qwant is used for private window tabs with Tor'?

Verification passed on

Brave	0.56.8 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Windows

• Verified below points for France region

  • Qwant is the default search egine for Normal tabs
  • Qwant is the default search egine for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

  Verified below points after changing default search engine to Bing

  • Bing is the default search engine for Normal tabs
  • Bing is the default search eginge for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

• Verified below points for Germany region

  • Qwant is the default search egine for Normal tabs
  • Qwant is the default search egine for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

  Verified below points after changing default search engine to Bing

  • Bing is the default search engine for Normal tabs
  • Bing is the default search eginge for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

• Verified below points for India/Real location region

  • DDG logo/wording shows for Private window tabs
  • DDG logo/wording shows for Private window tabs with tor
  • DDG is the default search engine for Private window tabs with tor

Verification passed on Windows 7 x64

Brave	0.56.8 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Windows 7 x64

• Verified below points for France region

  • Qwant is the default search egine for Normal tabs
  • Qwant is the default search egine for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

  Verified below points after changing default search engine to Bing

  • Bing is the default search engine for Normal tabs
  • Bing is the default search eginge for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

• Verified below points for Germany region

  • Qwant is the default search egine for Normal tabs
  • Qwant is the default search egine for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

  Verified below points after changing default search engine to Bing

  • Bing is the default search engine for Normal tabs
  • Bing is the default search eginge for Private window tabs
  • Qwant is the default search egine for Private window tabs with tor

• Verified below points for Poland region

  • DDG logo/wording shows for Private window tabs
  • DDG logo/wording shows for Private window tabs with tor
  • DDG is the default search engine for Private window tabs with tor

Verification passed on

Brave	0.56.8 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Linux

Region: France

• Verified default search engine is Qwant on Normal/Private/Tor windows
• Verified DDG info not shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses Qwant)
• Verified upgrade profile from previous install uses the previously set search engines

Region: Germany

• Verified default search engine is Qwant on Normal/Private/Tor windows
• Verified DDG info not shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses Qwant)
• Verified upgrade profile from previous install uses the previously set search engines

Region: Canada

• Verified default search engine is Google on Normal/Private windows
• Verified default search engine on Tor window is DDG
• Verified DDG info shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses DDG)
• Verified upgrade profile from previous install uses the previously set search engines

Verified passed with

Brave	0.56.8 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Mac OS X

Region: France

• Verified default search engine is Qwant on Normal/Private/Tor windows
• Verified DDG info not shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses Qwant)
• Verified upgrade profile from previous install uses the previously set search engines

Region: Germany

• Verified default search engine is Qwant on Normal/Private/Tor windows
• Verified DDG info not shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses Qwant)
• Verified upgrade profile from previous install uses the previously set search engines

Region: US

• Verified default search engine is Google on Normal/Private windows
• Verified default search engine on Tor window is DDG
• Verified DDG info shown on Private and Tor windows
• Verified changing default search engine on normal windows, changes it on private windows as well and not on Tor windows(still uses DDG)
• Verified upgrade profile from previous install uses the previously set search engines