[serial] Add monitor for device add/remove events on Windows

This change removes the old serial enumeration code on Windows and
always uses the new enumeration path while listening to window messages
to discover when ports are added and removed from the system.

This will allow us to keep the UI up-to-date in real time when the user
plugs in a device and deliver connection events to web apps.

Bug: 981483
Change-Id: I4126e370b02973458b5c2aac6a230244248b2320
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2099238
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751217}

base/win/windows_types.h

@@ -93,6 +93,7 @@ CHROME_DECLARE_HANDLE(HWND);
 typedef LPVOID HINTERNET;
 typedef HINSTANCE HMODULE;
 typedef PVOID LSA_HANDLE;
+typedef PVOID HDEVINFO;
 
 // Forward declare some Windows struct/typedef sets.
 
@@ -114,6 +115,8 @@ typedef struct tagMENUITEMINFOW MENUITEMINFOW, MENUITEMINFO;
 
 typedef struct tagNMHDR NMHDR;
 
+typedef struct _SP_DEVINFO_DATA SP_DEVINFO_DATA;
+
 typedef PVOID PSID;
 
 // Declare Chrome versions of some Windows structures. These are needed for

services/device/serial/serial_device_enumerator.cc

@@ -7,9 +7,32 @@
 #include <utility>
 
 #include "base/unguessable_token.h"
+#include "build/build_config.h"
+
+#if defined(OS_LINUX)
+#include "services/device/serial/serial_device_enumerator_linux.h"
+#elif defined(OS_MACOSX)
+#include "services/device/serial/serial_device_enumerator_mac.h"
+#elif defined(OS_WIN)
+#include "services/device/serial/serial_device_enumerator_win.h"
+#endif
 
 namespace device {
 
+// static
+std::unique_ptr<SerialDeviceEnumerator> SerialDeviceEnumerator::Create(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
+#if defined(OS_LINUX)
+  return std::make_unique<SerialDeviceEnumeratorLinux>();
+#elif defined(OS_MACOSX)
+  return std::make_unique<SerialDeviceEnumeratorMac>();
+#elif defined(OS_WIN)
+  return std::make_unique<SerialDeviceEnumeratorWin>(std::move(ui_task_runner));
+#else
+#error "No implementation of SerialDeviceEnumerator on this platform."
+#endif
+}
+
 SerialDeviceEnumerator::SerialDeviceEnumerator() = default;
 
 SerialDeviceEnumerator::~SerialDeviceEnumerator() = default;

services/device/serial/serial_device_enumerator.h

@@ -24,7 +24,8 @@ class SerialDeviceEnumerator {
  public:
   using TokenPathMap = std::map<base::UnguessableToken, base::FilePath>;
 
-  static std::unique_ptr<SerialDeviceEnumerator> Create();
+  static std::unique_ptr<SerialDeviceEnumerator> Create(
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
 
   SerialDeviceEnumerator();
   virtual ~SerialDeviceEnumerator();

services/device/serial/serial_device_enumerator_linux.cc

@@ -33,11 +33,6 @@ const char kRfcommMajor[] = "216";
 
 }  // namespace
 
-// static
-std::unique_ptr<SerialDeviceEnumerator> SerialDeviceEnumerator::Create() {
-  return std::make_unique<SerialDeviceEnumeratorLinux>();
-}
-
 SerialDeviceEnumeratorLinux::SerialDeviceEnumeratorLinux() {
   DETACH_FROM_SEQUENCE(sequence_checker_);
 

services/device/serial/serial_device_enumerator_mac.cc

@@ -104,11 +104,6 @@ bool GetUInt16Property(io_service_t service,
 
 }  // namespace
 
-// static
-std::unique_ptr<SerialDeviceEnumerator> SerialDeviceEnumerator::Create() {
-  return std::make_unique<SerialDeviceEnumeratorMac>();
-}
-
 SerialDeviceEnumeratorMac::SerialDeviceEnumeratorMac() {
   notify_port_.reset(IONotificationPortCreate(kIOMasterPortDefault));
   CFRunLoopAddSource(CFRunLoopGetMain(),

services/device/serial/serial_device_enumerator_unittest.cc

@@ -19,7 +19,7 @@ class SerialDeviceEnumeratorTest : public testing::Test {
       : task_environment_(base::test::TaskEnvironment::MainThreadType::IO) {}
   ~SerialDeviceEnumeratorTest() override = default;
 
- private:
+ protected:
   base::test::TaskEnvironment task_environment_;
 };
 
@@ -27,7 +27,8 @@ TEST_F(SerialDeviceEnumeratorTest, GetDevices) {
   // There is no guarantee that a test machine will have a serial device
   // available. The purpose of this test is to ensure that the process of
   // attempting to enumerate devices does not cause a crash.
-  auto enumerator = SerialDeviceEnumerator::Create();
+  auto enumerator = SerialDeviceEnumerator::Create(
+      task_environment_.GetMainThreadTaskRunner());
   ASSERT_TRUE(enumerator);
   std::vector<mojom::SerialPortInfoPtr> devices = enumerator->GetDevices();
 }

services/device/serial/serial_device_enumerator_win.h

@@ -5,10 +5,10 @@
 #ifndef SERVICES_DEVICE_SERIAL_SERIAL_DEVICE_ENUMERATOR_WIN_H_
 #define SERVICES_DEVICE_SERIAL_SERIAL_DEVICE_ENUMERATOR_WIN_H_
 
-#include <vector>
-
 #include "base/macros.h"
-#include "base/optional.h"
+#include "base/scoped_observer.h"
+#include "base/win/windows_types.h"
+#include "device/base/device_monitor_win.h"
 #include "services/device/serial/serial_device_enumerator.h"
 
 namespace device {
@@ -16,21 +16,35 @@ namespace device {
 // Discovers and enumerates serial devices available to the host.
 class SerialDeviceEnumeratorWin : public SerialDeviceEnumerator {
  public:
-  SerialDeviceEnumeratorWin();
+  SerialDeviceEnumeratorWin(
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
   ~SerialDeviceEnumeratorWin() override;
 
-  // Implementation for SerialDeviceEnumerator.
-  std::vector<mojom::SerialPortInfoPtr> GetDevices() override;
-
   // Searches for the COM port in the device's friendly name and returns the
   // appropriate device path or nullopt if the input did not contain a valid
   // name.
   static base::Optional<base::FilePath> GetPath(
       const std::string& friendly_name);
 
+  // SerialDeviceEnumerator
+  std::vector<mojom::SerialPortInfoPtr> GetDevices() override;
+  base::Optional<base::FilePath> GetPathFromToken(
+      const base::UnguessableToken& token) override;
+
+  void OnPathAdded(const base::string16& device_path);
+  void OnPathRemoved(const base::string16& device_path);
+
  private:
-  std::vector<mojom::SerialPortInfoPtr> GetDevicesNew();
-  std::vector<mojom::SerialPortInfoPtr> GetDevicesOld();
+  class UiThreadHelper;
+
+  void DoInitialEnumeration();
+  void EnumeratePort(HDEVINFO dev_info, SP_DEVINFO_DATA* dev_info_data);
+
+  std::map<base::UnguessableToken, mojom::SerialPortInfoPtr> ports_;
+  std::map<base::FilePath, base::UnguessableToken> paths_;
+
+  std::unique_ptr<UiThreadHelper, base::OnTaskRunnerDeleter> helper_;
+  base::WeakPtrFactory<SerialDeviceEnumeratorWin> weak_factory_{this};
 
   DISALLOW_COPY_AND_ASSIGN(SerialDeviceEnumeratorWin);
 };

services/device/serial/serial_port_manager_impl.cc

@@ -36,7 +36,7 @@ void SerialPortManagerImpl::SetSerialEnumeratorForTesting(
 
 void SerialPortManagerImpl::GetDevices(GetDevicesCallback callback) {
   if (!enumerator_)
-    enumerator_ = SerialDeviceEnumerator::Create();
+    enumerator_ = SerialDeviceEnumerator::Create(ui_task_runner_);
   std::move(callback).Run(enumerator_->GetDevices());
 }
 
@@ -45,7 +45,7 @@ void SerialPortManagerImpl::GetPort(
     mojo::PendingReceiver<mojom::SerialPort> receiver,
     mojo::PendingRemote<mojom::SerialPortConnectionWatcher> watcher) {
   if (!enumerator_)
-    enumerator_ = SerialDeviceEnumerator::Create();
+    enumerator_ = SerialDeviceEnumerator::Create(ui_task_runner_);
   base::Optional<base::FilePath> path = enumerator_->GetPathFromToken(token);
   if (path) {
     io_task_runner_->PostTask(