Adds associated interface support to IPC::Channel

Provides a way of registering associated interface bindings with
an IPC::Channel endpoint and acquiring proxies to remote interfaces
on the other side.

Support for this is exposed by IPC::Channel but only implemented
in IPC::ChannelMojo.

This is part a series of CLs to support Channel-associated interfaces.

BUG=612500

Committed: https://crrev.com/dc88e5075878f16cde23b910d2ce19aa862129e4
Review-Url: https://codereview.chromium.org/2137353002
Cr-Original-Commit-Position: refs/heads/master@{#405316}
Cr-Commit-Position: refs/heads/master@{#405364}
diff --git a/ipc/ipc_channel_mojo.cc b/ipc/ipc_channel_mojo.cc
index 22efa3a..70a12f4 100644
--- a/ipc/ipc_channel_mojo.cc
+++ b/ipc/ipc_channel_mojo.cc
@@ -307,6 +307,14 @@
   listener_->OnChannelError();
 }
 
+void ChannelMojo::OnAssociatedInterfaceRequest(
+    const std::string& name,
+    mojo::ScopedInterfaceEndpointHandle handle) {
+  auto iter = associated_interfaces_.find(name);
+  if (iter != associated_interfaces_.end())
+    iter->second.Run(std::move(handle));
+}
+
 void ChannelMojo::InitMessageReader(mojom::ChannelAssociatedPtrInfo sender,
                                     mojom::ChannelAssociatedRequest receiver,
                                     base::ProcessId peer_pid) {
@@ -392,6 +400,9 @@
   return bootstrap_->GetSelfPID();
 }
 
+Channel::AssociatedInterfaceSupport*
+ChannelMojo::GetAssociatedInterfaceSupport() { return this; }
+
 void ChannelMojo::OnMessageReceived(const Message& message) {
   TRACE_EVENT2("ipc,toplevel", "ChannelMojo::OnMessageReceived",
                "class", IPC_MESSAGE_ID_CLASS(message.type()),
@@ -468,4 +479,23 @@
   return MOJO_RESULT_OK;
 }
 
+mojo::AssociatedGroup* ChannelMojo::GetAssociatedGroup() {
+  DCHECK(bootstrap_);
+  return bootstrap_->GetAssociatedGroup();
+}
+
+void ChannelMojo::AddGenericAssociatedInterface(
+    const std::string& name,
+    const GenericAssociatedInterfaceFactory& factory) {
+  auto result = associated_interfaces_.insert({ name, factory });
+  DCHECK(result.second);
+}
+
+void ChannelMojo::GetGenericRemoteAssociatedInterface(
+    const std::string& name,
+    mojo::ScopedInterfaceEndpointHandle handle) {
+  DCHECK(message_reader_);
+  message_reader_->GetRemoteInterface(name, std::move(handle));
+}
+
 }  // namespace IPC