This makes debugging using graphics tools easier on Windows.

BUG=angleproject:1290
BUG=angleproject:1299

Change-Id: Ia3889c10fd8e23486f0122e0b567c470517bc9e0
Reviewed-on: https://chromium-review.googlesource.com/324821Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>