better names for web worker threads

platform/script-debugger/backend/src/WorkerManager.kt

@@ -19,5 +19,5 @@ package org.jetbrains.debugger
  * @author Konstantin.Ulitin
  */
 interface WorkerManager {
-  val activeWorkers: Set<String>
+  val activeWorkers: Map<String, WebWorker>
 }

platform/script-debugger/backend/src/WorkerManagerBase.kt

@@ -21,5 +21,5 @@ import java.util.*
  * @author Konstantin.Ulitin
  */
 abstract class WorkerManagerBase : WorkerManager {
-  override val activeWorkers: Set<String> = Collections.emptySet()
+  override val activeWorkers: Map<String, WebWorker> = Collections.emptyMap()
 }

platform/script-debugger/backend/src/org/jetbrains/debugger/WebWorker.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jetbrains.debugger
+
+
+/**
+ * @author Konstantin.Ulitin
+ */
+interface WebWorker {
+  val id: String
+  val url: String
+}