There were two problems (both fixed in this CL):
1) When we were resized by the view manager, we forgot to deflate by the
device-pixel-ratio when converting to engine types. That caused use to
allocate a backing texture that was 9x what we needed.
2) When the surfaces system returned textures to us for re-use, we'd put them
into the cache even if they were the old size. That caused us to thrash the
texture cache. In this CL, we make the size of the textures in the cache
explicit.
R=eseidel@chromium.org
BUG=449001
Review URL: https://codereview.chromium.org/868263002
