Revert 162179 "Initiate webfont download right after style recalc"

One of the two CLs that might cause fast/frames/seamless/seamless-nested-crash.html to timeout in debug.  Can't reproduce locally, so attempting reverting to confirm.  Will reland if wrong.

> Initiate webfont download right after style recalc
> 
> Currently WebFont download is queued during layout, and actual download is
> delayed until after layout. This patch makes CSSFontFace::willUseFontData()
> enqueue font download, which is called in style calc time. StyleResolver
> kicks off font downloads, along with other pending resources.
> 
> UMA metrics (WebFont.Resource.StyleRecalcToDownloadLatency) shows
> this reduces webfont download latency 114ms at the 50 percentile.
> This patch also removes FontResource::FontResourceHistograms as we
> collected sufficient data.
> 
> BUG=246492
> TEST=Covered by existing tests
> 
> Review URL: https://codereview.chromium.org/63713002

TBR=ksakamoto@chromium.org

Review URL: https://codereview.chromium.org/75763003

git-svn-id: svn://svn.chromium.org/blink/trunk@162249 bbb929c8-8fbe-4397-9dbb-9b2b20218538