handling of webrtc fingerprinting changed

[btlechowski]

Found when testing #3626
Handling of webrtc blocking changed from 0.60.x. Not sure if this is expected.
webrtc blocking is now more aggressive.

Steps to Reproduce

1. Clean profile
2. Open https://diafygi.github.io/webrtc-ips/

Actual result:

From 0.61.49

Expected result:

From 0.60.48

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	0.61.49 Chromium: 73.0.3683.67 (Official Build) (64-bit)
Revision	a83fd4f3207ae83412d329a9ca1239dd1e068345-refs/branch-heads/3683@{#760}
OS	Windows 7 Service Pack 1 Build 7601.24312

cc @brave/legacy_qa

[kjozwiak]

Reproduced on macOS 10.14.3 x64 using the following build:

Brave	0.61.49 Chromium: 73.0.3683.67 (Official Build) (64-bit)
Revision	a83fd4f3207ae83412d329a9ca1239dd1e068345-refs/branch-heads/3683@{#760}
OS	Mac OS X

[jumde]

Behavior is same on chrome and chrome canary.

[GeetaSarvadnya]

Reproduced on Linux Mint 0.61.49

Brave	0.61.49 Chromium: 73.0.3683.67 (Official Build) (64-bit)
Revision	a83fd4f3207ae83412d329a9ca1239dd1e068345-refs/branch-heads/3683@{#760}
OS	Linux mint

[rebron]

cc: @diracdeltas We don't have an option anymore, IP address is hidden and chromium has the same behavior without an adblocker. We ok with this behavior now?

[diracdeltas]

Seems fine if the default behavior is that the webrtc leak is blocked.