ipc: Remove unnecessary attachment broker plumbing.

ipc/mojo/ipc_mojo_bootstrap.h

Index: ipc/mojo/ipc_mojo_bootstrap.h
diff --git a/ipc/mojo/ipc_mojo_bootstrap.h b/ipc/mojo/ipc_mojo_bootstrap.h
index f22cedce766799334183b6f0f2929c29dc84c159..c1ee64c678492391ac9fa6810ff87bf31c9137ec 100644
--- a/ipc/mojo/ipc_mojo_bootstrap.h
+++ b/ipc/mojo/ipc_mojo_bootstrap.h
@@ -13,8 +13,6 @@
 
 namespace IPC {
 
-class AttachmentBroker;
-
 // MojoBootstrap establishes a bootstrap pipe between two processes in
 // Chrome. It creates a native IPC::Channel first, then sends one
 // side of a newly created pipe to peer process. The pipe is intended
@@ -39,8 +37,7 @@ class IPC_MOJO_EXPORT MojoBootstrap : public Listener {
   // mode as |mode|. The result is notified to passed |delegate|.
   static scoped_ptr<MojoBootstrap> Create(ChannelHandle handle,
                                           Channel::Mode mode,
-                                          Delegate* delegate,
-                                          AttachmentBroker* broker);
+                                          Delegate* delegate);
 
   MojoBootstrap();
   ~MojoBootstrap() override;