Revert of Move content's shell connections to the IO thread

services/shell/public/cpp/lib/connector_impl.cc

Index: services/shell/public/cpp/lib/connector_impl.cc
diff --git a/services/shell/public/cpp/lib/connector_impl.cc b/services/shell/public/cpp/lib/connector_impl.cc
index 84af8860bfeddec3f6ae9bb9971a5ac2df094f0a..73c6723eb521534a0081b2c7f9771b94813b4f11 100644
--- a/services/shell/public/cpp/lib/connector_impl.cc
+++ b/services/shell/public/cpp/lib/connector_impl.cc
@@ -19,12 +19,11 @@
 Connector::ConnectParams::~ConnectParams() {}
 
 ConnectorImpl::ConnectorImpl(mojom::ConnectorPtrInfo unbound_state)
-    : unbound_state_(std::move(unbound_state)) {
-  thread_checker_.DetachFromThread();
-}
+    : unbound_state_(std::move(unbound_state)) {}
 
 ConnectorImpl::ConnectorImpl(mojom::ConnectorPtr connector)
     : connector_(std::move(connector)) {
+  thread_checker_.reset(new base::ThreadChecker);
   connector_.set_connection_error_handler(
       base::Bind(&ConnectorImpl::OnConnectionError, base::Unretained(this)));
 }
@@ -32,7 +31,7 @@
 ConnectorImpl::~ConnectorImpl() {}
 
 void ConnectorImpl::OnConnectionError() {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(thread_checker_->CalledOnValidThread());
   connector_.reset();
 }
 
@@ -42,12 +41,23 @@
 }
 
 std::unique_ptr<Connection> ConnectorImpl::Connect(ConnectParams* params) {
-  if (!BindIfNecessary())
-    return nullptr;
+  // Bind this object to the current thread the first time it is used to
+  // connect.
+  if (!connector_.is_bound()) {
+    if (!unbound_state_.is_valid()) {
+      // It's possible to get here when the link to the shell has been severed
+      // (and so the connector pipe has been closed) but the app has chosen not
+      // to quit.
+      return nullptr;
+    }
+    connector_.Bind(std::move(unbound_state_));
+    connector_.set_connection_error_handler(
+        base::Bind(&ConnectorImpl::OnConnectionError, base::Unretained(this)));
+    thread_checker_.reset(new base::ThreadChecker);
+  }
+  DCHECK(thread_checker_->CalledOnValidThread());
 
-  DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(params);
-
   // We allow all interfaces on outgoing connections since we are presumably in
   // a position to know who we're talking to.
   CapabilityRequest request;
@@ -102,41 +112,9 @@
 }
 
 std::unique_ptr<Connector> ConnectorImpl::Clone() {
-  if (!BindIfNecessary())
-    return nullptr;
-
   mojom::ConnectorPtr connector;
-  mojom::ConnectorRequest request = GetProxy(&connector);
-  connector_->Clone(std::move(request));
-  return base::MakeUnique<ConnectorImpl>(connector.PassInterface());
-}
-
-bool ConnectorImpl::BindIfNecessary() {
-  // Bind this object to the current thread the first time it is used to
-  // connect.
-  if (!connector_.is_bound()) {
-    if (!unbound_state_.is_valid()) {
-      // It's possible to get here when the link to the shell has been severed
-      // (and so the connector pipe has been closed) but the app has chosen not
-      // to quit.
-      return false;
-    }
-
-    // Bind the ThreadChecker to this thread.
-    DCHECK(thread_checker_.CalledOnValidThread());
-
-    connector_.Bind(std::move(unbound_state_));
-    connector_.set_connection_error_handler(
-        base::Bind(&ConnectorImpl::OnConnectionError, base::Unretained(this)));
-  }
-
-  return true;
-}
-
-std::unique_ptr<Connector> Connector::Create(mojom::ConnectorRequest* request) {
-  mojom::ConnectorPtr proxy;
-  *request = mojo::GetProxy(&proxy);
-  return base::MakeUnique<ConnectorImpl>(proxy.PassInterface());
+  connector_->Clone(GetProxy(&connector));
+  return base::WrapUnique(new ConnectorImpl(connector.PassInterface()));
 }
 
 }  // namespace shell