Fix ArcBridgeBootstrap race issues.

components/arc/arc_bridge_service_impl.cc

Index: components/arc/arc_bridge_service_impl.cc
diff --git a/components/arc/arc_bridge_service_impl.cc b/components/arc/arc_bridge_service_impl.cc
index 7b8a11edc690d059690070b1817503759c0ae4f0..0aabf5526553909425b06ef97d9cce58fe03f64d 100644
--- a/components/arc/arc_bridge_service_impl.cc
+++ b/components/arc/arc_bridge_service_impl.cc
@@ -18,7 +18,6 @@
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/dbus_method_call_status.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
-#include "chromeos/dbus/session_manager_client.h"
 #include "components/arc/arc_bridge_host_impl.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
@@ -31,14 +30,10 @@ namespace {
 constexpr int64_t kReconnectDelayInSeconds = 5;
 }  // namespace
 
-ArcBridgeServiceImpl::ArcBridgeServiceImpl(
-    std::unique_ptr<ArcBridgeBootstrap> bootstrap)
-    : bootstrap_(std::move(bootstrap)),
-      session_started_(false),
-      weak_factory_(this) {
+ArcBridgeServiceImpl::ArcBridgeServiceImpl()
+    : session_started_(false), weak_factory_(this) {
   DCHECK(!g_arc_bridge_service);
   g_arc_bridge_service = this;
-  bootstrap_->set_delegate(this);
 }
 
 ArcBridgeServiceImpl::~ArcBridgeServiceImpl() {
@@ -78,7 +73,11 @@ void ArcBridgeServiceImpl::PrerequisitesChanged() {
       return;
     VLOG(0) << "Prerequisites met, starting ARC";
     SetStopReason(StopReason::SHUTDOWN);
+
     SetState(State::CONNECTING);
+    bootstrap_ =
+        delegate_ ? delegate_->CreateBootstrap() : ArcBridgeBootstrap::Create();
+    bootstrap_->set_delegate(this);
     bootstrap_->Start();
   } else {
     if (session_started_)
@@ -95,13 +94,16 @@ void ArcBridgeServiceImpl::StopInstance() {
     return;
   }
 
+  // We were explicitly asked to stop, so do not reconnect.
+  reconnect_ = false;
+
   VLOG(1) << "Stopping ARC";
+  DCHECK(bootstrap_.get());
   SetState(State::STOPPING);
   arc_bridge_host_.reset();
-  bootstrap_->Stop();
 
-  // We were explicitly asked to stop, so do not reconnect.
-  reconnect_ = false;
+  // Note: this can call OnStopped() internally as a callback.
+  bootstrap_->Stop();
 }
 
 void ArcBridgeServiceImpl::OnConnectionEstablished(
@@ -123,10 +125,11 @@ void ArcBridgeServiceImpl::OnConnectionEstablished(
 
 void ArcBridgeServiceImpl::OnStopped(StopReason stop_reason) {
   DCHECK(CalledOnValidThread());
+  VLOG(0) << "ARC stopped: " << static_cast<int>(stop_reason);
   arc_bridge_host_.reset();
+  bootstrap_.reset();
   SetStopReason(stop_reason);
   SetState(State::STOPPED);
-  VLOG(0) << "ARC stopped";
 
   if (reconnect_) {
     // There was a previous invocation and it crashed for some reason. Try