Revert of Disable DWriteFontCache loading on startup as a LightSpeed experiment (patchset #1 id:1 of https://codereview.chromium.org/1225203003/ )
Revert of Disable DWriteFontCache loading on startup as a LightSpeed experiment (patchset #1 id:1 of https://codereview.chromium.org/1225203003/ )

Reason for revert:
The experiment is over -- see http://crbug.com/508642 for results and discussion.

Original issue's description:
> Disable DWriteFontCache loading on startup as a LightSpeed experiment
>
> Our experiment on the effect of user profile's file cache has suggested that
> there may be a performance gain on startup (measured by
>     Startup.FirstWebContents.NonEmptyPaint) by disabling DWriteFontCache loading
> in PostProfileInit and forcing the browser to rebuild the cache every time after
> a 30s delay. This is a LightSpeed experiment to test our speculation in Canary.
>
> The experiment is documented here:
> https://docs.google.com/document/d/1Mly9bOSqxGcSfhOcvpEzvItTcVAdm5jsOXdieTlrcu4/edit
>
> BUG=508642
>
> Committed: https://crrev.com/f4b448dc53f01fab9dd08126c524cf1053c4cfe7
> Cr-Commit-Position: refs/heads/master@{#338307}

TBR=thakis@chromium.org,tiany@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=508642

Review URL: https://codereview.chromium.org/1318613003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#345857}

CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,ltilve/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend,CapOM/ChromiumGStreamerBackend