chrome:// urls should display as brave://

[petemill]

It may be too much work to redirect all chrome:// urls to brave:// and have the appropriate handlers and checks still work reliable.

Luckily, the ToolbarModel provides GetURLForDisplay which can be overridden so that brave:// displays most of the time (until the URL is edited).

When paired with #810 this should cover quite a bit of the requirement to support brave:// URLs without confusing the users about the chromium-based core.

Test plan:

Displays brave:// url

• Clean Profile
• Launch browser
• Welcome page should be open with brave://welcome as the address in LocationBar

Edits chrome:// url

• Open settings
• Settings page should be open with brave:// prefix in LocationBar
• Edit the url by focusing in the LocationBar and moving the cursor or adding text
• LocationBar text should have chrome:// prefix

Copies chrome:// url

• Open settings
• Settings page should be open with brave:// prefix in LocationBar
• Right-click the LocationBar text and select 'Copy'
• Clipboard text should have chrome:// prefix

[srirambv]

Verification Passed on

Brave	0.55.14 Chromium: 70.0.3538.54 (Official Build) beta(64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Linux

Went through verification using the following build under macOS 10.13.6 x64 - PASSED

Brave	0.55.14 Chromium: 70.0.3538.54 (Official Build) beta(64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Mac OS X

• went through about 70% of the links under brave://about and ensured they worked with brave://

Verification Passed on

Brave	0.55.14 Chromium: 70.0.3538.54 (Official Build) beta (64-bit)
Revision	4f8e578b6680574714e9ed3bb9f02922b4dde40d-refs/branch-heads/3538@{#937}
OS	Windows