Add GraphicsContext parameter to FontPlatformData::setupPaint

Add a GraphicsContext parameter to FontPlatformDataHarfBuzz::setupPaint
and change Font::drawGlyphs in FontHarfBuzz.cpp to pass the context
object when calling setupPaint.

This matches the windows code path and allows the setup call to check
flags on the context, as required by the FontPlatformDataChromiumWin
implementation to determine whether LCD text should be used.

BUG=313423
R=leviw@chromium.org

Review URL: https://codereview.chromium.org/52383003

git-svn-id: svn://svn.chromium.org/blink/trunk@161211 bbb929c8-8fbe-4397-9dbb-9b2b20218538