Delete WebFontInfo::renderStyleForStrike().

Remove Blink's code to query Fontconfig for rendering
settings on Linux; the sandbox uses gfx::FontRenderParams
instead now. (Fontconfig is still used by Blink for
fallback.)

Also remove WebFontInfo::setSubpixelPositioning() and merge
the getRenderStyleForStrike() helper function into
FontPlatformData::querySystemForRenderStyle().

BUG=395313

Review URL: https://codereview.chromium.org/427883003

git-svn-id: svn://svn.chromium.org/blink/trunk@179322 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rename the FastTextAutosizer "TextAutosizer"

Now that the FastTextAutosizer has shipped and the old TextAutosizer
has been removed, we can drop the 'Fast' prefix. The only non-
mechanical change in this patch is an update to the comment
above deepestBlockContainingAllText to not refer to the old autosizer.

In addition to renaming the TextAutosizer, this patch removes the
runtime flag from chrome://flags.

No new tests as there should be no change in behavior.

This patch depends on:
https://codereview.chromium.org/346303007/

BUG=385380

Review URL: https://codereview.chromium.org/427213002

git-svn-id: svn://svn.chromium.org/blink/trunk@179323 bbb929c8-8fbe-4397-9dbb-9b2b20218538