Implement tab indicator for WebUSB.

device/usb/mojo/device_impl.cc

 // Copyright 2015 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 "device/usb/mojo/device_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <numeric>
@@ skipping 128 matching lines @@
   //  * the message pipe it is bound to is closed
   observer_.Add(device_.get());
   binding_.set_connection_error_handler([this]() { delete this; });
 }
 
 DeviceImpl::~DeviceImpl() {
   CloseHandle();
 }
 
 void DeviceImpl::CloseHandle() {
-  if (device_handle_)
+  if (device_handle_) {
     device_handle_->Close();
+    if (permission_provider_)
+      permission_provider_->DecrementConnectionCount();
+  }
   device_handle_ = nullptr;
 }
 
 bool DeviceImpl::HasControlTransferPermission(
     ControlTransferRecipient recipient,
     uint16_t index) {
   DCHECK(device_handle_);
   const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
 
   if (!permission_provider_)
@@ skipping 26 matching lines @@
         config->configuration_value, *device_info_);
   } else {
     // Client must already have device permission to have gotten this far.
     return true;
   }
 }
 
 void DeviceImpl::OnOpen(const OpenCallback& callback,
                         scoped_refptr<UsbDeviceHandle> handle) {
   device_handle_ = handle;
+  if (device_handle_ && permission_provider_)
+    permission_provider_->IncrementConnectionCount();
   callback.Run(handle ? OpenDeviceError::OK : OpenDeviceError::ACCESS_DENIED);
 }
 
 void DeviceImpl::GetDeviceInfo(const GetDeviceInfoCallback& callback) {
   const UsbConfigDescriptor* config = device_->GetActiveConfiguration();
   device_info_->active_configuration = config ? config->configuration_value : 0;
   callback.Run(device_info_->Clone());
 }
 
 void DeviceImpl::Open(const OpenCallback& callback) {
@@ skipping 235 matching lines @@
       base::Bind(&OnIsochronousTransferOut, base::Passed(&callback_ptr)));
 }
 
 void DeviceImpl::OnDeviceRemoved(scoped_refptr<UsbDevice> device) {
   DCHECK_EQ(device_, device);
   delete this;
 }
 
 }  // namespace usb
 }  // namespace device