Respect kRectsMustMatchForMSAASrc_BlitFramebufferFlag in dst setup

Crurently, when preparing a texture for blitFramebuffer, we ignore the
kRectsMustMatchForMSAASrc_BlitFramebufferFlag, and may attempt to
copy from one src rect to a different dst rect.

This change updates initDescForDstCopy and setupDstTexture to allocate
larger textures if necessary and accomodate this flags requirements.

Bug: 658277
Change-Id: I9f45a03d4055e0ad87c01e1d826287695096e609
Reviewed-on: https://skia-review.googlesource.com/10941
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
9 files changed