Read HID report descriptor from sysfs and request permission on connect.

extensions/browser/api/hid/hid_api.cc

 // Copyright 2014 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 "extensions/browser/api/hid/hid_api.h"
 
 #include <string>
 #include <vector>
 
 #include "device/core/device_client.h"
@@ skipping 123 matching lines @@
 
 HidConnectFunction::~HidConnectFunction() {}
 
 bool HidConnectFunction::Prepare() {
   parameters_ = hid::Connect::Params::Create(*args_);
   EXTENSION_FUNCTION_VALIDATE(parameters_.get());
   return true;
 }
 
 void HidConnectFunction::AsyncWorkStart() {
-  device::HidDeviceInfo device_info;
-  if (!device_manager_->GetDeviceInfo(parameters_->device_id, &device_info)) {
+  if (!device_manager_->GetDeviceInfo(parameters_->device_id, &device_info_)) {
     CompleteWithError(kErrorInvalidDeviceId);
     return;
   }
 
-  if (!device_manager_->HasPermission(extension(), device_info)) {
+  if (!device_manager_->HasPermission(extension(), device_info_)) {
     LOG(WARNING) << "Insufficient permissions to access device.";
     CompleteWithError(kErrorPermissionDenied);
     return;
   }
 
-  HidService* hid_service = device::DeviceClient::Get()->GetHidService();
-  DCHECK(hid_service);
+  hid_service_ = device::DeviceClient::Get()->GetHidService();

[Yoyo Zhou, 2014/10/10 23:05:24]

This can be inside the ifdef

+  DCHECK(hid_service_);
+
+#if defined(OS_CHROMEOS)
+  hid_service_->RequestAccess(
+      device_info_.device_id,
+      base::Bind(&HidConnectFunction::OnRequestAccessComplete, this));
+#else
+  OnRequestAccessComplete(true);
+#endif
+}
+
+void HidConnectFunction::OnRequestAccessComplete(bool success) {
+  if (!success) {
+    CompleteWithError(kErrorPermissionDenied);
+    return;
+  }
+
   scoped_refptr<HidConnection> connection =
-      hid_service->Connect(device_info.device_id);
+      hid_service_->Connect(device_info_.device_id);
   if (!connection.get()) {
     CompleteWithError(kErrorFailedToOpenDevice);
     return;
   }
+
   int connection_id = connection_manager_->Add(
       new HidConnectionResource(extension_->id(), connection));
   SetResult(PopulateHidConnection(connection_id, connection));
   AsyncWorkCompleted();
 }
 
 HidDisconnectFunction::HidDisconnectFunction() {}
 
 HidDisconnectFunction::~HidDisconnectFunction() {}
 
@@ skipping 163 matching lines @@
 
 void HidSendFeatureReportFunction::OnFinished(bool success) {
   if (!success) {
     CompleteWithError(kErrorTransfer);
     return;
   }
   AsyncWorkCompleted();
 }
 
 }  // namespace extensions