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

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/shell/public/cpp/lib/connector_impl.h"
 
 #include "base/memory/ptr_util.h"
 #include "services/shell/public/cpp/identity.h"
 #include "services/shell/public/cpp/lib/connection_impl.h"
 
 namespace shell {
 
 Connector::ConnectParams::ConnectParams(const Identity& target)
     : target_(target) {}
 
 Connector::ConnectParams::ConnectParams(const std::string& name)
     : target_(name, mojom::kInheritUserID) {}
 
 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)));
 }
 
 ConnectorImpl::~ConnectorImpl() {}
 
 void ConnectorImpl::OnConnectionError() {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(thread_checker_->CalledOnValidThread());
   connector_.reset();
 }
 
 std::unique_ptr<Connection> ConnectorImpl::Connect(const std::string& name) {
   ConnectParams params(name);
   return Connect(&params);
 }
 
 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;
   request.interfaces.insert("*");
   mojom::InterfaceProviderPtr local_interfaces;
   mojom::InterfaceProviderRequest local_request = GetProxy(&local_interfaces);
   mojom::InterfaceProviderPtr remote_interfaces;
   mojom::InterfaceProviderRequest remote_request = GetProxy(&remote_interfaces);
   std::unique_ptr<internal::ConnectionImpl> registry(
       new internal::ConnectionImpl(
@@ skipping 34 matching lines @@
     return std::move(registry);
   }
   connector_->Connect(mojom::Identity::From(params->target()),
                       std::move(remote_request), std::move(local_interfaces),
                       std::move(client_process_connection),
                       registry->GetConnectCallback());
   return std::move(registry);
 }
 
 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