cc: Move RasterBuffer implementations from ResourceProvider to RasterWorkerPool implementations.

Each RasterWorkerPool implementation is tied to some
RasterBuffer implementation. By moving the RasterBuffer
code into RasterWorkerPool implementation this
relationship becomes more explicit and more easily
adjusted for the need of the RasterWorkerPool
implementation.

BUG=406404

Review URL: https://codereview.chromium.org/562833004

Cr-Commit-Position: refs/heads/master@{#295528}
23 files changed