Mojo bindings: merge the control messages of sending disconnect reason and notifying endpoint close…

ipc/ipc_mojo_bootstrap.cc

Index: ipc/ipc_mojo_bootstrap.cc
diff --git a/ipc/ipc_mojo_bootstrap.cc b/ipc/ipc_mojo_bootstrap.cc
index 3ba136619a6bd920a3f0929284c5e4927f14f913..256f394ec0a8281f7d556fe75a936e6a88d8c7f3 100644
--- a/ipc/ipc_mojo_bootstrap.cc
+++ b/ipc/ipc_mojo_bootstrap.cc
@@ -161,7 +161,10 @@ class ChannelAssociatedGroupController
     return CreateScopedInterfaceEndpointHandle(id, true);
   }
 
-  void CloseEndpointHandle(mojo::InterfaceId id, bool is_local) override {
+  void CloseEndpointHandle(
+      mojo::InterfaceId id,
+      bool is_local,
+      const base::Optional<mojo::DisconnectReason>& reason) override {
     if (!mojo::IsValidInterfaceId(id))
       return;
 
@@ -182,8 +185,8 @@ class ChannelAssociatedGroupController
     MarkClosedAndMaybeRemove(endpoint);
 
     base::AutoUnlock unlocker(lock_);
-    if (!mojo::IsMasterInterfaceId(id))
-      control_message_proxy_.NotifyPeerEndpointClosed(id);
+    if (!mojo::IsMasterInterfaceId(id) || reason)
+      control_message_proxy_.NotifyPeerEndpointClosed(id, reason);
   }
 
   mojo::InterfaceEndpointController* AttachEndpointClient(
@@ -264,6 +267,15 @@ class ChannelAssociatedGroupController
       peer_closed_ = true;
     }
 
+    const base::Optional<mojo::DisconnectReason>& disconnect_reason() const {
+      return disconnect_reason_;
+    }
+
+    void set_disconnect_reason(
+        const base::Optional<mojo::DisconnectReason>& disconnect_reason) {
+      disconnect_reason_ = disconnect_reason;
+    }
+
     base::SingleThreadTaskRunner* task_runner() const {
       return task_runner_.get();
     }
@@ -436,6 +448,7 @@ class ChannelAssociatedGroupController
 
     bool closed_ = false;
     bool peer_closed_ = false;
+    base::Optional<mojo::DisconnectReason> disconnect_reason_;
     mojo::InterfaceEndpointClient* client_ = nullptr;
     scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
     std::unique_ptr<mojo::SyncHandleWatcher> sync_watcher_;
@@ -538,9 +551,11 @@ class ChannelAssociatedGroupController
     DCHECK(endpoint->task_runner() && endpoint->client());
     if (endpoint->task_runner()->BelongsToCurrentThread() && !force_async) {
       mojo::InterfaceEndpointClient* client = endpoint->client();
+      base::Optional<mojo::DisconnectReason> reason(
+          endpoint->disconnect_reason());
 
       base::AutoUnlock unlocker(lock_);
-      client->NotifyError();
+      client->NotifyError(reason);
     } else {
       endpoint->task_runner()->PostTask(
           FROM_HERE,
@@ -721,15 +736,18 @@ class ChannelAssociatedGroupController
   }
 
   // mojo::PipeControlMessageHandlerDelegate:
-  bool OnPeerAssociatedEndpointClosed(mojo::InterfaceId id) override {
+  bool OnPeerAssociatedEndpointClosed(
+      mojo::InterfaceId id,
+      const base::Optional<mojo::DisconnectReason>& reason) override {
     DCHECK(thread_checker_.CalledOnValidThread());
 
-    if (mojo::IsMasterInterfaceId(id))
-      return false;
+    DCHECK(!mojo::IsMasterInterfaceId(id) || reason);
 
     scoped_refptr<ChannelAssociatedGroupController> keepalive(this);
     base::AutoLock locker(lock_);
     scoped_refptr<Endpoint> endpoint = FindOrInsertEndpoint(id, nullptr);
+    if (reason)
+      endpoint->set_disconnect_reason(reason);
     if (!endpoint->peer_closed()) {
       if (endpoint->client())
         NotifyEndpointOfError(endpoint.get(), false /* force_async */);
@@ -752,7 +770,7 @@ class ChannelAssociatedGroupController
       MarkClosedAndMaybeRemove(endpoint);
     }
 
-    control_message_proxy_.NotifyPeerEndpointClosed(id);
+    control_message_proxy_.NotifyPeerEndpointClosed(id, base::nullopt);
     return true;
   }