Temporary workaround for "brave scheme is loaded from js"

[bbondy]

Test Plan

• Prevent loading brave scheme url from javascript brave-core#1196

Original Filed Issue

This is to track a temporary fix for this issue:
#2777

[btlechowski]

Verification passed on

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Windows 7

Used test plan from brave/brave-core#1196
Test case 1 PASS - brave://settings is not loaded after 2.5 seconds
Test case 2 is invalid for 0.58.x, because there is no Change your search engine page in welcome page. Used other link in the welcome page and they work as expected
Test case 3 PASS, used flag --enable-brave-sync

Verification passed on

Brave	0.59.21 Chromium: 72.0.3626.28 (Official Build) beta (64-bit)
Revision	997b1040b63bac324e815797ba52be0cd8f616ed-refs/branch-heads/3626@{#461}
OS	Windows 7

Used test plan from brave/brave-core#1196
All TCs PASSED

Verification PASSED on Mint 19.1 x64 VM using the following build:

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Linux

• Reproduced the original issues using 0.58.18 Chromium: 71.0.3578.98
• Went through Prevent loading brave scheme url from javascript brave-core#1196 and verified that all the cases are working as expected
• Used brave-browser --enable-brave-sync to enable Sync under 0.58.20 Chromium: 71.0.3578.98
• Regarding TC#2, Search Engine selection via brave://welcome isn't implemented, ensured other screens opened brave://settings correctly.

Verification PASSED on macOS 10.14.2 x64 using the following build:

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Mac OS X

• Reproduced the original issues using 0.58.18 Chromium: 71.0.3578.98
• Went through Prevent loading brave scheme url from javascript brave-core#1196 and verified that all the cases are working as expected
• Used /Applications/Brave\ Browser.app/Contents/MacOS/Brave\ Browser --enable-brave-sync to enable Sync under 0.58.20 Chromium: 71.0.3578.98
• Regarding TC#2, Search Engine selection via brave://welcome isn't implemented, ensured other screens opened brave://settings correctly.