Fixed open a new tab in same session as session tab

[tarasglek]

Test plan

#7684 (comment)

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• Did you search for similar issues before submitting this one?
  yes

• Describe the issue you encountered:
  Brendan was talking me through using session tabs, but Brave didn't act as Brendan suggested it would :)

• Platform (Win7, 8, 10? macOS? Linux distro?):
  All

• Brave Version (revision SHA):
  Latest/71d8ffc(linux)

• Steps to reproduce:
  1.File/New Session Tab
  2.File/New Tab

• Actual result:
  Step 2 opens a tab in default session

• Expected result:
  Step 2 opens another tab in same session.

• Any related issues:
  Between this issue and until issue 7367 is resolved, session tabs are of limited use.

[bbondy]

@bradleyrichter I think we need click and hold on new tab button to have a submenu under session tab for the created sessions. Thoughts? We should do this soon.

[bsclifton]

related #7417

[bradleyrichter]

@bbondy that should work. We also want to make sure that child tabs from a new session parent tab are set correctly. One request is to allow this for control + T as well.

…

On Feb 28, 2017, at 8:00 AM, Brian R. Bondy ***@***.***> wrote: @bradleyrichter I think we need click and hold on new tab button to have a submenu under session tab for the created sessions. Thoughts? We should do this soon. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[bsclifton]

Moving to 0.13.7