Allow default font size changing on Linux.
Currently base rendering font size on Linux is hardcoded to 16.0 with no possibility of changing it. This patch add such possibility in RendererPreferences.
Webkit part: https://codereview.chromium.org/
570243002/
This was once landed and reverted:
https://codereview.chromium.org/
549303004 (original)
https://codereview.chromium.org/
1319613004 (revert)
due to unexpected default font size change.
Now this CL removes the problematic part to derive the default font
size from desktop environment.
BUG=525176
TBR=joleksy@opera.com, jochen@chromium.org, erg@chromium.org, jln@chromium.org
Review URL: https://codereview.chromium.org/
1303163008
Cr-Commit-Position: refs/heads/master@{#346353}