Fix 7645: Enable remote debugging by default and proxy devtools request

[jumde]

Resolves brave/brave-browser#7645

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
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  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

1. Navigate to example.com
2. Open developer tools > Audit - Generate Report
3. Should work without any issues.

Reviewer Checklist:

• New files have MPL-2.0 license header.
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• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.

[bridiver]

can we not use the normal static redirect? My concern is that we're changing urls in different places and that makes it harder to find how/where/what we're changing

[jumde]

@bridiver - I was trying that first, but it requires a much bigger re-write of the code.

Currently, the brave-proxy code lives in brave_proxying_url_loader_factory.cc which lives in //brave/browser/net. To use static redirect we need to invoke MaybeProxyRequest from devtools_instrumentation::WillCreateURLLoaderFactory which is present in //content/browser and we cannot add a deps for //brave/browser/net to //content/browser.

So for static redirect to work, we'll need to move the proxying code to //content/ or //net.

[iefremov]

@jumde do you remember if we have an issue for moving proxying code to //net? At least brave_system_request_handler.cc. I guess this is not the first layering problem with this

[jumde]

@iefremov - Filed one: brave/brave-browser#9770 - Thanks for the reminder.

[bsclifton]

Changes LGTM - but when running locally on Windows, it starts working and then gets to the generating report part. Unfortunately, that seems to close dev tools? Not sure if something is not being proxied properly?

Will try a signed executable tomorrow (from PR builder) to see if it makes a difference

[bsclifton]

Release version works as expected! 😄 Nice work here

[bsclifton]

As mentioned in the issue, I believe what I ran into is captured w/ https://bugs.chromium.org/p/chromium/issues/detail?id=1036525