MB 200: Update the Mullvad Browser Windows installer.

Merge Info

Related Issues

• tor-browser#xxxxx
• mullvad-browser#200 (closed)
• tor-browser-build#

Backporting

Timeline

• Immediate: patchset needed as soon as possible
• Next Minor Stable Release: patchset that needs to be verified in nightly before backport
• Eventually: patchset that needs to be verified in alpha before backport
• No Backport (preferred): patchset for the next major stable

(Optional) Justification

• Emergency security update: patchset fixes CVEs, 0-days, etc
• Censorship event: patchset enables censorship circumvention
• Critical bug-fix: patchset fixes a bug in core-functionality
• Consistency: patchset which would make development easier if it were in both the alpha and release branches; developer tools, build system changes, etc
• Sponsor required: patchset required for sponsor
• Other: please explain

Issue Tracking

• Link resolved issues with appropriate Release Prep issue for changelog generation

Review

Request Reviewer

• Request review from an applications developer depending on modified system:
  • NOTE: if the MR modifies multiple areas, please /cc all the relevant reviewers (since gitlab only allows 1 reviewer)
  • accessibility : henry
  • android : clairehurst, dan
  • build system : boklm
  • extensions : ma1
  • firefox internals (XUL/JS/XPCOM) : ma1
  • fonts : pierov
  • frontend (implementation) : henry
  • frontend (review) : donuts, richard
  • localization : henry, pierov
  • macos : clairehurst, dan
  • nightly builds : boklm
  • rebases/release-prep : boklm, dan, ma1, pierov, richard
  • security : ma1
  • signing : boklm, richard
  • updater : pierov
  • misc/other : pierov, richard

Change Description

This MR brings the first set of changes from sajolida's mockups to nightly:

• the selection of standard/custom installation now looks like the welcome page
  • I had to reimplement a page that looks like the built-in one to reduce the description label's height. The alternative would have been to call Win32 functions with the system plugin. Completely re-implementing the page looked a better idea, since we'll have to customize all the texts anyway
• after installing, the browser is started and we close the installer automatically

After this, the only remaining work for the installer (in my opinion) is to add the definitive strings and setup a localization pipeline.

How Tested

Built and ran https://tb-build-03.torproject.org/~pierov/testbuild/mullvad-browser-windows-x86_64-install-testbuild-200-installer-1.exe.