Change renderer compositor command buffer to be 64kB

With delegated rendering and either software rasterization or GPU rasterization in a worker context, the compositor context will execute very few commands. Therefore, we can reduce the size of the command buffer from 1MB to 64kB with no effect on performance.

Review URL: https://codereview.chromium.org/1263213004

Cr-Commit-Position: refs/heads/master@{#341874}
2 files changed