[usb] Remove active configuration cache

This change removes the |active_configuration_| variable so that a
pointer to the mojom::ConfigurationInfo for the active configuration is
no longer cached and is instead computed based on configuration value
of the currently selected active configuration.

Bug: 1016596
Change-Id: If84f0a5207d6743d775d2f314b4f341a2dcc707e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873919
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Auto-Submit: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Ovidio de Jesús Ruiz-Henríquez <odejesush@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708325}

services/device/usb/mojo/device_impl.cc

@@ -130,7 +130,7 @@ bool DeviceImpl::HasControlTransferPermission(
     return true;
   }
 
-  const mojom::UsbConfigurationInfo* config = device_->active_configuration();
+  const mojom::UsbConfigurationInfo* config = device_->GetActiveConfiguration();
   if (!config)
     return false;
 
@@ -218,7 +218,7 @@ void DeviceImpl::ClaimInterface(uint8_t interface_number,
     return;
   }
 
-  const mojom::UsbConfigurationInfo* config = device_->active_configuration();
+  const mojom::UsbConfigurationInfo* config = device_->GetActiveConfiguration();
   if (!config) {
     std::move(callback).Run(false);
     return;

services/device/usb/usb_device.cc

@@ -73,6 +73,14 @@ uint16_t UsbDevice::device_version() const {
   return GetDeviceVersion(*device_info_);
 }
 
+const mojom::UsbConfigurationInfo* UsbDevice::GetActiveConfiguration() const {
+  for (const auto& config : configurations()) {
+    if (config->configuration_value == device_info_->active_configuration)
+      return config.get();
+  }
+  return nullptr;
+}
+
 void UsbDevice::CheckUsbAccess(ResultCallback callback) {
   // By default assume that access to the device is allowed. This is implemented
   // on Chrome OS by checking with permission_broker.
@@ -99,12 +107,6 @@ void UsbDevice::RemoveObserver(Observer* observer) {
 
 void UsbDevice::ActiveConfigurationChanged(int configuration_value) {
   device_info_->active_configuration = configuration_value;
-  for (const auto& config : configurations()) {
-    if (config->configuration_value == configuration_value) {
-      active_configuration_ = config.get();
-      return;
-    }
-  }
 }
 
 void UsbDevice::NotifyDeviceRemoved() {

services/device/usb/usb_device.h

@@ -92,9 +92,7 @@ class UsbDevice : public base::RefCountedThreadSafe<UsbDevice> {
   const std::vector<mojom::UsbConfigurationInfoPtr>& configurations() const {
     return device_info_->configurations;
   }
-  const mojom::UsbConfigurationInfo* active_configuration() const {
-    return active_configuration_;
-  }
+  const mojom::UsbConfigurationInfo* GetActiveConfiguration() const;
 
   // On ChromeOS the permission_broker service must be used to open USB devices.
   // This function asks it to check whether a future Open call will be allowed.
@@ -156,11 +154,6 @@ class UsbDevice : public base::RefCountedThreadSafe<UsbDevice> {
   void OnDisconnect();
   void HandleClosed(UsbDeviceHandle* handle);
 
-  // The current device configuration descriptor. May be null if the device is
-  // in an unconfigured state; if not null, it is a pointer to one of the
-  // items in |descriptor_.configurations|.
-  const mojom::UsbConfigurationInfo* active_configuration_ = nullptr;
-
   // Weak pointers to open handles. HandleClosed() will be called before each
   // is freed.
   std::list<UsbDeviceHandle*> handles_;

services/device/usb/usb_device_handle_impl.cc

@@ -1000,7 +1000,7 @@ void UsbDeviceHandleImpl::RefreshEndpointMap() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(device_);
   endpoint_map_.clear();
-  const mojom::UsbConfigurationInfo* config = device_->active_configuration();
+  const mojom::UsbConfigurationInfo* config = device_->GetActiveConfiguration();
   if (!config)
     return;
 

services/device/usb/usb_device_handle_usbfs.cc

@@ -872,7 +872,7 @@ void UsbDeviceHandleUsbfs::RefreshEndpointInfo() {
   DCHECK(device_);
   endpoints_.clear();
 
-  const mojom::UsbConfigurationInfo* config = device_->active_configuration();
+  const mojom::UsbConfigurationInfo* config = device_->GetActiveConfiguration();
   if (!config)
     return;
 

services/device/usb/usb_device_handle_win.cc

@@ -491,9 +491,9 @@ UsbDeviceHandleWin::UsbDeviceHandleWin(scoped_refptr<UsbDeviceWin> device,
       blocking_task_runner_(UsbService::CreateBlockingTaskRunner()) {
   DCHECK(!composite);
   // Windows only supports configuration 1, which therefore must be active.
-  DCHECK(device_->active_configuration());
+  DCHECK(device_->GetActiveConfiguration());
 
-  for (const auto& interface : device_->active_configuration()->interfaces) {
+  for (const auto& interface : device_->GetActiveConfiguration()->interfaces) {
     for (const auto& alternate : interface->alternates) {
       if (alternate->alternate_setting != 0)
         continue;