cc: Remove redundant BufferIdAllocator

BufferIdAllocator was unnescessarily getting created in
ResourceProvider's ctor as it was not being used anywhere.
This commit removes IdAllocator/BufferIdAllocator class
and its allocation.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2751953003
Cr-Commit-Position: refs/heads/master@{#457427}
3 files changed