tree f9dbfce8ef00f01ddd760d10bf54d557c2ff7ff3
parent 73571e66051374fb0f8fee3c954e5c05ed0ceeb4
author Jamie Madill <jmadill@chromium.org> 1398365457 -0400
committer Jamie Madill <jmadill@chromium.org> 1398715622 +0000

Lazy creation of the BufferStorage staging buffer.

Only creating the staging buffer on use saves us from allocating
a D3D11 staging buffer for pack buffers. This saves some memory
and time when we're only using a buffer object for asynchronous
readback.

BUG=angle:511

Change-Id: I97b37cc27aba4a4526025815b5935b9e74abae2e
Reviewed-on: https://chromium-review.googlesource.com/195367
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
(cherry picked from commit ebf396c1dd243223240bac6ea7f01a23893f9a28)
Reviewed-on: https://chromium-review.googlesource.com/197281