serial: Add option to switch enumeration methods

A potential solution for issue 1119497 is to switch from enumerating
devices implementing GUID_DEVINTERFACE_COMPORT to using the "bus
enumerator" identified by GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR.

I'm putting this behind a flag so that developers can try it out in
canary-channel. If it works I can enable it by default and keep the flag
around for a couple releases in case it causes other problems.

Bug: 1119497
Change-Id: Icad9008799ed331c3da15e5a70e0184144c47a58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2417460
Commit-Queue: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Reviewed-by: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Auto-Submit: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808368}

chrome/browser/about_flags.cc

@@ -6433,6 +6433,13 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(printing::features::kEnableOopPrintDrivers)},
 #endif
 
+#if defined(OS_WIN)
+    {"use-serial-bus-enumerator",
+     flag_descriptions::kUseSerialBusEnumeratorName,
+     flag_descriptions::kUseSerialBusEnumeratorDescription, kOsWin,
+     FEATURE_VALUE_TYPE(features::kUseSerialBusEnumerator)},
+#endif
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

chrome/browser/flag-metadata.json

@@ -4545,6 +4545,11 @@
     "owners": [ "khorimoto", "zentaro" ],
     "expiry_milestone": 85
   },
+  {
+    "name": "use-serial-bus-enumerator",
+    "owners": [ "reillyg" ],
+    "expiry_milestone": 89
+  },
   {
     "name": "use-sync-sandbox",
     "owners": [ "//components/sync/OWNERS" ],

chrome/browser/flag_descriptions.cc

@@ -3452,6 +3452,11 @@ const char kUseAngleD3D11[] = "D3D11";
 const char kUseAngleD3D9[] = "D3D9";
 const char kUseAngleD3D11on12[] = "D3D11on12";
 
+const char kUseSerialBusEnumeratorName[] = "Use system serial port enumerator";
+const char kUseSerialBusEnumeratorDescription[] =
+    "Use the system-supplied enumerator for serial port devices instead of "
+    "enumerating devices implementing the COM port interface.";
+
 const char kUseWinrtMidiApiName[] = "Use Windows Runtime MIDI API";
 const char kUseWinrtMidiApiDescription[] =
     "Use Windows Runtime MIDI API for WebMIDI (effective only on Windows 10 or "

chrome/browser/flag_descriptions.h

@@ -1975,6 +1975,9 @@ extern const char kUseAngleD3D11[];
 extern const char kUseAngleD3D9[];
 extern const char kUseAngleD3D11on12[];
 
+extern const char kUseSerialBusEnumeratorName[];
+extern const char kUseSerialBusEnumeratorDescription[];
+
 extern const char kUseWinrtMidiApiName[];
 extern const char kUseWinrtMidiApiDescription[];
 

services/device/public/cpp/device_features.cc

@@ -23,4 +23,12 @@ const base::Feature kWinrtGeolocationImplementation{
 const base::Feature kMacCoreLocationImplementation{
     "kMacCoreLocationImplementation", base::FEATURE_ENABLED_BY_DEFAULT};
 
+#if defined(OS_WIN)
+// Switches from enumerating serial ports using GUID_DEVINTERFACE_SERIALPORT to
+// GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR. This is an experimental solution to
+// https://crbug.com/1119497.
+const base::Feature kUseSerialBusEnumerator{"UseSerialBusEnumerator",
+                                            base::FEATURE_DISABLED_BY_DEFAULT};
+#endif  // defined(OS_WIN)
+
 }  // namespace features

services/device/public/cpp/device_features.h

@@ -9,6 +9,7 @@
 #define SERVICES_DEVICE_PUBLIC_CPP_DEVICE_FEATURES_H_
 
 #include "base/feature_list.h"
+#include "build/build_config.h"
 #include "services/device/public/cpp/device_features_export.h"
 
 namespace features {
@@ -22,6 +23,10 @@ DEVICE_FEATURES_EXPORT extern const base::Feature
 DEVICE_FEATURES_EXPORT extern const base::Feature
     kMacCoreLocationImplementation;
 
+#if defined(OS_WIN)
+DEVICE_FEATURES_EXPORT extern const base::Feature kUseSerialBusEnumerator;
+#endif  // defined(OS_WIN)
+
 }  // namespace features
 
 #endif  // SERVICES_DEVICE_PUBLIC_CPP_DEVICE_FEATURES_H_

services/device/serial/BUILD.gn

@@ -55,6 +55,7 @@ if (is_win || ((is_linux || is_chromeos) && use_udev) || is_mac) {
       "//device/bluetooth/public/cpp",
       "//mojo/public/cpp/bindings",
       "//net",
+      "//services/device/public/cpp:device_features",
       "//services/device/public/cpp/bluetooth:bluetooth",
       "//services/device/public/cpp/serial:switches",
     ]

services/device/serial/serial_device_enumerator_win.cc

@@ -19,6 +19,7 @@
 #include <string>
 #include <utility>
 
+#include "base/feature_list.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/numerics/ranges.h"
 #include "base/scoped_generic.h"
@@ -30,6 +31,7 @@
 #include "base/threading/scoped_blocking_call.h"
 #include "base/win/registry.h"
 #include "base/win/scoped_devinfo.h"
+#include "services/device/public/cpp/device_features.h"
 #include "third_party/re2/src/re2/re2.h"
 
 namespace device {
@@ -110,6 +112,13 @@ bool GetProductID(const std::string& instance_id, uint32_t* product_id) {
          base::HexStringToUInt(product_id_str, product_id);
 }
 
+const GUID& GetDeviceInterfaceGuid() {
+  if (base::FeatureList::IsEnabled(features::kUseSerialBusEnumerator))
+    return GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR;
+
+  return GUID_DEVINTERFACE_COMPORT;
+}
+
 }  // namespace
 
 class SerialDeviceEnumeratorWin::UiThreadHelper
@@ -131,7 +140,7 @@ class SerialDeviceEnumeratorWin::UiThreadHelper
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     enumerator_ = std::move(enumerator);
     device_observer_.Add(
-        DeviceMonitorWin::GetForDeviceInterface(GUID_DEVINTERFACE_COMPORT));
+        DeviceMonitorWin::GetForDeviceInterface(GetDeviceInterfaceGuid()));
   }
 
   void OnDeviceAdded(const GUID& class_guid,
@@ -239,7 +248,7 @@ void SerialDeviceEnumeratorWin::DoInitialEnumeration() {
                                                 base::BlockingType::MAY_BLOCK);
   // Make a device interface query to find all serial devices.
   base::win::ScopedDevInfo dev_info(
-      SetupDiGetClassDevs(&GUID_DEVINTERFACE_COMPORT, nullptr, 0,
+      SetupDiGetClassDevs(&GetDeviceInterfaceGuid(), nullptr, 0,
                           DIGCF_DEVICEINTERFACE | DIGCF_PRESENT));
   if (!dev_info.is_valid())
     return;

tools/metrics/histograms/enums.xml

@@ -41976,6 +41976,7 @@ from previous Chrome versions.
       label="AutofillSaveCardDialogUnlabeledExpirationDate:disabled"/>
   <int value="-697751423" label="disable-quickoffice-component-app"/>
   <int value="-696693295" label="Canvas2DImageChromium:disabled"/>
+  <int value="-696225611" label="UseSerialBusEnumerator:disabled"/>
   <int value="-695687521" label="double-buffer-compositing"/>
   <int value="-694622753" label="VizHitTest:disabled"/>
   <int value="-694187898" label="MashOopViz:disabled"/>
@@ -42538,6 +42539,7 @@ from previous Chrome versions.
   <int value="-94335249" label="UseAAudioDriver:enabled"/>
   <int value="-92116820" label="InlineUpdateFlow:enabled"/>
   <int value="-91767554" label="enable-de-jelly"/>
+  <int value="-91370149" label="UseSerialBusEnumerator:enabled"/>
   <int value="-90521375" label="PDFTwoUpView:enabled"/>
   <int value="-90032223" label="BuiltInModuleInfra:disabled"/>
   <int value="-89690053" label="MaterialDesignUserManager:enabled"/>