ipc: Remove unnecessary attachment broker plumbing.

ipc/ipc_channel.h

Index: ipc/ipc_channel.h
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index 06555d333de03dc565a8bed0d25a75461577eca2..7aa3ab0654dc7d4663e4555431c768bba9fcb201 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -22,7 +22,6 @@
 
 namespace IPC {
 
-class AttachmentBroker;
 class Listener;
 
 //------------------------------------------------------------------------------
@@ -120,22 +119,13 @@ class IPC_EXPORT Channel : public Endpoint {
   // Each mode has its own Create*() API to create the Channel object.
   //
   // TODO(morrita): Replace CreateByModeForProxy() with one of above Create*().
-  //
-  // TODO(erikchen): Remove default parameter for |broker|. It exists only to
-  // make the upcoming refactor decomposable into smaller CLs.
-  // http://crbug.com/493414.
   static scoped_ptr<Channel> Create(const IPC::ChannelHandle& channel_handle,
                                     Mode mode,
-                                    Listener* listener,
-                                    AttachmentBroker* broker = nullptr);
+                                    Listener* listener);
 
-  // TODO(erikchen): Remove default parameter for |broker|. It exists only to
-  // make the upcoming refactor decomposable into smaller CLs.
-  // http://crbug.com/493414.
   static scoped_ptr<Channel> CreateClient(
       const IPC::ChannelHandle& channel_handle,
-      Listener* listener,
-      AttachmentBroker* broker = nullptr);
+      Listener* listener);
 
   // Channels on Windows are named by default and accessible from other
   // processes. On POSIX channels are anonymous by default and not accessible
@@ -144,28 +134,21 @@ class IPC_EXPORT Channel : public Endpoint {
   // MODE_NAMED_CLIENT is equivalent to MODE_CLIENT.
   static scoped_ptr<Channel> CreateNamedServer(
       const IPC::ChannelHandle& channel_handle,
-      Listener* listener,
-      AttachmentBroker* broker);
+      Listener* listener);
   static scoped_ptr<Channel> CreateNamedClient(
       const IPC::ChannelHandle& channel_handle,
-      Listener* listener,
-      AttachmentBroker* broker);
+      Listener* listener);
 #if defined(OS_POSIX)
   // An "open" named server accepts connections from ANY client.
   // The caller must then implement their own access-control based on the
   // client process' user Id.
   static scoped_ptr<Channel> CreateOpenNamedServer(
       const IPC::ChannelHandle& channel_handle,
-      Listener* listener,
-      AttachmentBroker* broker);
+      Listener* listener);
 #endif
-  // TODO(erikchen): Remove default parameter for |broker|. It exists only to
-  // make the upcoming refactor decomposable into smaller CLs.
-  // http://crbug.com/493414.
   static scoped_ptr<Channel> CreateServer(
       const IPC::ChannelHandle& channel_handle,
-      Listener* listener,
-      AttachmentBroker* broker = nullptr);
+      Listener* listener);
 
   ~Channel() override;