IPC: Make ChannelReader inherit from SupportsAttachmentBrokering.
Each IPC::Channel will have a reference to an AttachmentBroker. This is
accomplished by requiring each of the Channel::Create methods to have a
|broker| parameter. For now, the |broker| parameter has a default value of
nullptr. This default parameter only exists so that this CL and subsequent
refactors can be decomposed into smaller CLs. The default parameter will be
removed once all callers of Channel::Create have been updated to pass in an
appropriate broker.
BUG=493414
Review URL: https://codereview.chromium.org/1185133006
Cr-Commit-Position: refs/heads/master@{#334699}
CrOS-Libchrome-Original-Commit: 27aa7d8b9e17ed5dd8f6b247c87ae7988f61d793
27 files changed