Revert "Hide SkCanvas getDevice() & getTopDevice()}"

Revert "Hide SkCanvas getDevice() & getTopDevice()}"

This reverts commit 76467a11a0aa4ba15f0f2e3ee078ba9b6ecbaa91.

Reason for revert: we may need to revert the Chromium GDI change.

Original change's description:
> Hide SkCanvas getDevice() & getTopDevice()}
>
> No longer used externally.
>
> R=reed@google.com
>
> Change-Id: I450148010852c2567d136d2c85c8837c6dcbc6b9
> Reviewed-on: https://skia-review.googlesource.com/6974
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Florin Malita <fmalita@chromium.org>
>

TBR=fmalita@chromium.org,reed@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: If8480aa5d36ff843c28409a5c94d51570ba0fc1c
Reviewed-on: https://skia-review.googlesource.com/6991
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Florin Malita <fmalita@google.com>