Change gpu::Buffer and gpu::BufferBacking to use uint32_t sizes

Because client and service may be of different bitness, offsets in command
buffers have to fit in a uint32_t, effectively limiting transfer buffers
to 4GB. This makes it clearer by enforcing it on IPC boundaries and
using uint32_t for the size, removing casts along the way.

Bug: 905509
Change-Id: Iabd9d01e5a8c93c8efea909a6df7d588de14c4fb
Commit-Queue: Antoine Labour <>
Reviewed-by: Zhenyao Mo <>
Cr-Original-Commit-Position: refs/heads/master@{#620510}
Cr-Mirrored-Commit: 1316afd20fa9d507cb13bfb1edf1b0d064689c15
1 file changed