Support USB device hotplug on Android.

device/usb/usb_service_android.cc

Index: device/usb/usb_service_android.cc
diff --git a/device/usb/usb_service_android.cc b/device/usb/usb_service_android.cc
index aa620d456657494ac745c3b5a7e238141206f02b..f867a2bc481c592cdda1362288d1fd1dee179d61 100644
--- a/device/usb/usb_service_android.cc
+++ b/device/usb/usb_service_android.cc
@@ -11,10 +11,12 @@
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "components/device_event_log/device_event_log.h"
 #include "device/usb/usb_device_android.h"
 #include "jni/ChromeUsbService_jni.h"
 
 using base::android::AttachCurrentThread;
+using base::android::JavaRef;
 using base::android::ScopedJavaLocalRef;
 
 namespace device {
@@ -25,31 +27,81 @@ bool UsbServiceAndroid::RegisterJNI(JNIEnv* env) {
 }
 
 UsbServiceAndroid::UsbServiceAndroid() {
-  j_object_.Reset(Java_ChromeUsbService_create(
-      AttachCurrentThread(), base::android::GetApplicationContext()));
-}
-
-UsbServiceAndroid::~UsbServiceAndroid() {}
-
-scoped_refptr<UsbDevice> UsbServiceAndroid::GetDevice(const std::string& guid) {
-  return nullptr;
-}
-
-void UsbServiceAndroid::GetDevices(const GetDevicesCallback& callback) {
   JNIEnv* env = AttachCurrentThread();
+  j_object_.Reset(
+      Java_ChromeUsbService_create(env, base::android::GetApplicationContext(),
+                                   reinterpret_cast<jlong>(this)));
   ScopedJavaLocalRef<jobjectArray> devices =
       Java_ChromeUsbService_getDevices(env, j_object_.obj());
   jsize length = env->GetArrayLength(devices.obj());
-
-  std::vector<scoped_refptr<UsbDevice>> results;
   for (jsize i = 0; i < length; ++i) {
-    ScopedJavaLocalRef<jobject> raw_device(
+    ScopedJavaLocalRef<jobject> usb_device(
         env, env->GetObjectArrayElement(devices.obj(), i));
-    results.push_back(UsbDeviceAndroid::Create(env, raw_device));
+    scoped_refptr<UsbDeviceAndroid> device(
+        UsbDeviceAndroid::Create(env, usb_device));
+    AddDevice(device);
   }
+}
+
+UsbServiceAndroid::~UsbServiceAndroid() {
+  JNIEnv* env = AttachCurrentThread();
+  Java_ChromeUsbService_close(env, j_object_.obj());
+}
+
+scoped_refptr<UsbDevice> UsbServiceAndroid::GetDevice(const std::string& guid) {
+  auto it = devices_by_guid_.find(guid);
+  if (it == devices_by_guid_.end())
+    return nullptr;
+  return it->second;
+}
 
+void UsbServiceAndroid::GetDevices(const GetDevicesCallback& callback) {
+  std::vector<scoped_refptr<UsbDevice>> devices;
+  devices.reserve(devices_by_guid_.size());
+  for (const auto& map_entry : devices_by_guid_)
+    devices.push_back(map_entry.second);
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
-                                                base::Bind(callback, results));
+                                                base::Bind(callback, devices));
+}
+
+void UsbServiceAndroid::DeviceAttached(JNIEnv* env,
+                                       const JavaRef<jobject>& caller,
+                                       const JavaRef<jobject>& usb_device) {
+  scoped_refptr<UsbDeviceAndroid> device(
+      UsbDeviceAndroid::Create(env, usb_device));
+  AddDevice(device);
+  NotifyDeviceAdded(device);
+}
+
+void UsbServiceAndroid::DeviceDetached(JNIEnv* env,
+                                       const JavaRef<jobject>& caller,
+                                       jint device_id) {
+  auto it = devices_by_id_.find(device_id);
+  if (it == devices_by_id_.end())
+    return;
+
+  scoped_refptr<UsbDeviceAndroid> device = it->second;
+  devices_by_id_.erase(it);
+  devices_by_guid_.erase(device->guid());
+
+  USB_LOG(USER) << "USB device removed: id=" << device->device_id()
+                << " guid=" << device->guid();
+
+  NotifyDeviceRemoved(device);
+}
+
+void UsbServiceAndroid::AddDevice(scoped_refptr<UsbDeviceAndroid> device) {
+  DCHECK(!ContainsKey(devices_by_id_, device->device_id()));
+  DCHECK(!ContainsKey(devices_by_guid_, device->guid()));
+  devices_by_id_[device->device_id()] = device;
+  devices_by_guid_[device->guid()] = device;
+
+  USB_LOG(USER) << "USB device added: id=" << device->device_id()
+                << " vendor=" << device->vendor_id() << " \""
+                << device->manufacturer_string()
+                << "\", product=" << device->product_id() << " \""
+                << device->product_string() << "\", serial=\""
+                << device->serial_number() << "\", guid=" << device->guid();
 }
 
 }  // namespace device