Revert of [mojo-edk] Simplify multiprocess pipe bootstrap

mojo/edk/system/core.cc

Index: mojo/edk/system/core.cc
diff --git a/mojo/edk/system/core.cc b/mojo/edk/system/core.cc
index d0b7b67f82a6459f77695d4324efa87c7879e70b..aad9541642fcad64ef94c40dc7cfd2ef8feeceae 100644
--- a/mojo/edk/system/core.cc
+++ b/mojo/edk/system/core.cc
@@ -44,9 +44,19 @@
 // This is an unnecessarily large limit that is relatively easy to enforce.
 const uint32_t kMaxHandlesPerMessage = 1024 * 1024;
 
-// TODO: Maybe we could negotiate a debugging pipe ID for cross-process pipes
-// too; for now we just use a constant. This only affects bootstrap pipes.
-const uint64_t kUnknownPipeIdForDebug = 0x7f7f7f7f7f7f7f7fUL;
+void OnPortConnected(
+    Core* core,
+    int endpoint,
+    const base::Callback<void(ScopedMessagePipeHandle)>& callback,
+    const ports::PortRef& port) {
+  // TODO: Maybe we could negotiate a pipe ID for cross-process pipes too;
+  // for now we just use 0x7F7F7F7F7F7F7F7F. In practice these are used for
+  // bootstrap and aren't passed around, so tracking them is less important.
+  MojoHandle handle = core->AddDispatcher(
+      new MessagePipeDispatcher(core->GetNodeController(), port,
+                                0x7f7f7f7f7f7f7f7fUL, endpoint));
+  callback.Run(ScopedMessagePipeHandle(MessagePipeHandle(handle)));
+}
 
 }  // namespace
 
@@ -150,37 +160,32 @@
   GetNodeController()->RequestShutdown(on_shutdown);
 }
 
-ScopedMessagePipeHandle Core::CreateMessagePipe(
-    ScopedPlatformHandle platform_handle) {
-  ports::PortRef port0, port1;
-  GetNodeController()->node()->CreatePortPair(&port0, &port1);
-  MojoHandle handle = AddDispatcher(
-    new MessagePipeDispatcher(GetNodeController(), port0,
-                              kUnknownPipeIdForDebug, 0));
+void Core::CreateMessagePipe(
+    ScopedPlatformHandle platform_handle,
+    const base::Callback<void(ScopedMessagePipeHandle)>& callback) {
+  ports::PortRef port;
+  GetNodeController()->node()->CreateUninitializedPort(&port);
   RemoteMessagePipeBootstrap::Create(
-      GetNodeController(), std::move(platform_handle), port1);
-  return ScopedMessagePipeHandle(MessagePipeHandle(handle));
-}
-
-ScopedMessagePipeHandle Core::CreateParentMessagePipe(
-    const std::string& token) {
-  ports::PortRef port0, port1;
-  GetNodeController()->node()->CreatePortPair(&port0, &port1);
-  MojoHandle handle = AddDispatcher(
-      new MessagePipeDispatcher(GetNodeController(), port0,
-                                kUnknownPipeIdForDebug, 0));
-  GetNodeController()->ReservePort(token, port1);
-  return ScopedMessagePipeHandle(MessagePipeHandle(handle));
-}
-
-ScopedMessagePipeHandle Core::CreateChildMessagePipe(const std::string& token) {
-  ports::PortRef port0, port1;
-  GetNodeController()->node()->CreatePortPair(&port0, &port1);
-  MojoHandle handle = AddDispatcher(
-      new MessagePipeDispatcher(GetNodeController(), port0,
-                                kUnknownPipeIdForDebug, 1));
-  GetNodeController()->MergePortIntoParent(token, port1);
-  return ScopedMessagePipeHandle(MessagePipeHandle(handle));
+      GetNodeController(), std::move(platform_handle), port,
+      base::Bind(&OnPortConnected, base::Unretained(this), 0, callback, port));
+}
+
+void Core::CreateParentMessagePipe(
+    const std::string& token,
+    const base::Callback<void(ScopedMessagePipeHandle)>& callback) {
+  GetNodeController()->ReservePort(
+      token,
+      base::Bind(&OnPortConnected, base::Unretained(this), 0, callback));
+}
+
+void Core::CreateChildMessagePipe(
+    const std::string& token,
+    const base::Callback<void(ScopedMessagePipeHandle)>& callback) {
+  ports::PortRef port;
+  GetNodeController()->node()->CreateUninitializedPort(&port);
+  GetNodeController()->ConnectToParentPort(
+      port, token,
+      base::Bind(&OnPortConnected, base::Unretained(this), 1, callback, port));
 }
 
 MojoResult Core::AsyncWait(MojoHandle handle,