Improve TranslatedVertexBuffer::map performance

TRAC #11392

- Don't use the identity translation buffer, but always copy into a streaming buffer.

Signed-off-by: Shannon Woods
Signed-off-by: Daniel Koch

Author:    Andrew Lewycky

git-svn-id: https://angleproject.googlecode.com/svn/trunk@264 736b8ea6-26fd-11df-bfd4-992fa37f6226
3 files changed