Icons color should be contrast to the theme color

[pvamshi]

Description

The light theme icons color need to be changed according to theme. The disabled icon looks darker while the active icon is lighter ( which on lighter theme makes the effect reversed).

Steps to Reproduce

1. Change default theme to a lighter theme
2. Navigate to any website

Actual result:

This is how the icons look like on light theme

Expected result:

It should be in contrast to the theme similar to what it is in dark background
The same in dark theme

Reproduces how often:

Always

Brave version (brave://version info)

Brave | 0.60.45 
Chromium: 72.0.3626.109 (Official Build)unknown (64-bit)
Revision | fae8db7ab9280fa6704a59980263c804f809ebd5-refs/branch-heads/3626@{#857}
OS | Linux

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds?
  Not sure. Didnt check in dev builds

Website problems only:

Not related to website

Additional Information

---

[bsclifton]

cc: @petemill