5 files changed, 26 insertions, 4 deletions
diff --git a/ipc/chromium/gtest/moz.build b/ipc/chromium/gtest/moz.build
index afa175c638..a1af974b16 100644
--- a/ipc/chromium/gtest/moz.build
+++ b/ipc/chromium/gtest/moz.build
@@ -8,9 +8,14 @@ Library("ipcchromiumtest")
 
 SOURCES += [
     "name_unittest.cc",
-    "ports_unittest.cc",
 ]
 
+# Bug 1837550 - Fails under TSAN
+if not CONFIG["MOZ_TSAN"]:
+    SOURCES += [
+        "ports_unittest.cc",
+    ]
+
 include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul-gtest"
diff --git a/ipc/chromium/gtest/ports_unittest.cc b/ipc/chromium/gtest/ports_unittest.cc
index bfa8214799..705bab7edb 100644
--- a/ipc/chromium/gtest/ports_unittest.cc
+++ b/ipc/chromium/gtest/ports_unittest.cc
@@ -237,6 +237,10 @@ class TestNode : public NodeDelegate {
     }
   }
 
+  void ObserveRemoteNode(const NodeName& node) override {
+    DCHECK(node != node_name_);
+  }
+
   void ClosePortsInEvent(Event* event) {
     if (event->type() != Event::Type::kUserMessage) {
       return;
diff --git a/ipc/chromium/src/base/revocable_store.cc b/ipc/chromium/src/base/revocable_store.cc
index b3d7414ee2..0b8a0655bd 100644
--- a/ipc/chromium/src/base/revocable_store.cc
+++ b/ipc/chromium/src/base/revocable_store.cc
@@ -25,9 +25,7 @@ RevocableStore::~RevocableStore() {
   owning_reference_->set_store(NULL);
 }
 
-void RevocableStore::Add(Revocable* item) {
-  DCHECK(!item->revoked());
-}
+void RevocableStore::Add(Revocable* item) { DCHECK(!item->revoked()); }
 
 void RevocableStore::RevokeAll() {
   // We revoke all the existing items in the store and reset our count.
diff --git a/ipc/chromium/src/mojo/core/ports/node.cc b/ipc/chromium/src/mojo/core/ports/node.cc
index 935771eeb7..036c981cbb 100644
--- a/ipc/chromium/src/mojo/core/ports/node.cc
+++ b/ipc/chromium/src/mojo/core/ports/node.cc
@@ -837,6 +837,10 @@ int Node::OnObserveProxy(const PortRef& port_ref,
     MaybeResendAckRequest(port_ref);
 
     delegate_->PortStatusChanged(port_ref);
+
+    if (event->proxy_target_node_name() != name_) {
+      delegate_->ObserveRemoteNode(event->proxy_target_node_name());
+    }
   }
 
   return OK;
@@ -1513,6 +1517,11 @@ int Node::AcceptPort(const PortName& port_name,
                           mozilla::MakeUnique<PortAcceptedEvent>(
                               port_descriptor.referring_port_name,
                               kInvalidPortName, kInvalidSequenceNum));
+
+  if (port_descriptor.peer_node_name != name_) {
+    delegate_->ObserveRemoteNode(port_descriptor.peer_node_name);
+  }
+
   return OK;
 }
 
diff --git a/ipc/chromium/src/mojo/core/ports/node_delegate.h b/ipc/chromium/src/mojo/core/ports/node_delegate.h
index 3172779c06..37fb67613a 100644
--- a/ipc/chromium/src/mojo/core/ports/node_delegate.h
+++ b/ipc/chromium/src/mojo/core/ports/node_delegate.h
@@ -29,6 +29,12 @@ class NodeDelegate {
   // to query the latest status of the port. Note, this event could be spurious
   // if another thread is simultaneously modifying the status of the port.
   virtual void PortStatusChanged(const PortRef& port_ref) = 0;
+
+  // Called after receiving a port with a remote peer, or bypassing a proxy to a
+  // remote peer. Embedders can use this to ensure a connection to the remote
+  // peer, reducing message queueing and ensuring prompt notification of peer
+  // node death.
+  virtual void ObserveRemoteNode(const NodeName& node) = 0;
 };
 
 }  // namespace ports