diff --git a/tools/chrome-rdp/src/main/js/chrome/contentscript.js b/tools/chrome-rdp/src/main/js/chrome/contentscript.js
index 5859f1799..c8f1334ff 100644
--- a/tools/chrome-rdp/src/main/js/chrome/contentscript.js
+++ b/tools/chrome-rdp/src/main/js/chrome/contentscript.js
@@ -14,13 +14,13 @@
  *  limitations under the License.
  */
 
-var connected = false;
-window.addEventListener("message", function(event) {
+let connected = false;
+window.addEventListener("message", (event) => {
     if (event.source !== window) {
         return;
     }
 
-    var data = event.data;
+    const data = event.data;
     if (typeof data.teavmDebugger !== "undefined" && !connected) {
         connected = true;
         chrome.runtime.sendMessage({ command: "debug", port: data.teavmDebugger.port });
diff --git a/tools/chrome-rdp/src/main/js/chrome/main.js b/tools/chrome-rdp/src/main/js/chrome/main.js
index 555d7806a..131a0f169 100644
--- a/tools/chrome-rdp/src/main/js/chrome/main.js
+++ b/tools/chrome-rdp/src/main/js/chrome/main.js
@@ -1,110 +1,144 @@
-debuggerAgentMap = {};
+debuggerAgentMap = Object.create(null);
+
+class DebuggerAgent {
+    constructor(tab, port) {
+        this.pendingMessages = [];
+        this.connection = null;
+        this.attachedToDebugger = false;
+        this.messageBuffer = "";
+        this.port = 0;
+        this.disconnectCallbacks = null;
+
+        this.debuggee = { tabId : tab.id };
+        this.port = port;
+        debuggerAgentMap[tab.id] = this;
+    }
+
+    attach() {
+        chrome.debugger.attach(this.debuggee, "1.2", () => {
+            this.attachedToDebugger = true;
+            chrome.debugger.sendCommand(this.debuggee, "Debugger.enable", {}, () => this.connectToServer());
+        });
+    }
+
+    connectToServer() {
+        this.connection = new WebSocket("ws://localhost:" + this.port + "/");
+        this.connection.onmessage = event => {
+            const str = event.data;
+            const ctl = str.substring(0, 1);
+            this.messageBuffer += str.substring(1);
+            if (ctl === '.') {
+                this.receiveMessage(JSON.parse(this.messageBuffer));
+                this.messageBuffer = "";
+            }
+        };
+        this.connection.onclose = () => {
+            if (this.connection != null) {
+                this.connection = null;
+                this.disconnect();
+            }
+        };
+        this.connection.onopen = () => {
+            for (const pendingMessage of this.pendingMessages) {
+                this.sendMessage(pendingMessage);
+            }
+            this.pendingMessages = null;
+        };
+    }
+
+    receiveMessage(message) {
+        chrome.debugger.sendCommand(this.debuggee, message.method, message.params, response => {
+            if (message.id) {
+                const responseToServer = {
+                    id : message.id,
+                    result : response,
+                    error : response ? void 0 : chrome.runtime.lastError
+                };
+                this.sendMessage(responseToServer);
+            }
+        });
+    }
+
+    sendMessage(message) {
+        let str = JSON.stringify(message);
+        while (str.length > DebuggerAgent.MAX_MESSAGE_SIZE) {
+            const part = "," + str.substring(0, DebuggerAgent.MAX_MESSAGE_SIZE);
+            this.connection.send(part);
+            str = str.substring(DebuggerAgent.MAX_MESSAGE_SIZE);
+        }
+        this.connection.send("." + str);
+    }
+
+    disconnect(callback) {
+        if (this.connection) {
+            const conn = this.connection;
+            this.connection = null;
+            conn.close();
+        }
+        if (this.attachedToDebugger) {
+            chrome.debugger.detach(this.debuggee, () => {
+                if (this.debuggee) {
+                    delete debuggerAgentMap[this.debuggee.tabId];
+                    this.debuggee = null;
+                }
+                for (const callback of this.disconnectCallbacks) {
+                    callback();
+                }
+                this.disconnectCallbacks = null;
+            });
+            this.attachedToDebugger = false;
+            this.disconnectCallbacks = [];
+        }
+
+        if (callback) {
+            if (this.disconnectCallbacks != null) {
+                this.disconnectCallbacks.push(callback);
+            } else {
+                callback();
+            }
+        }
+    }
+}
+
+DebuggerAgent.MAX_MESSAGE_SIZE = 65534;
 
 chrome.browserAction.onClicked.addListener(function(tab) {
-    chrome.storage.sync.get({
-        port: 2357,
-    }, function(items) {
-        new DebuggerAgent(tab, items.port).attach();
-    });
+    chrome.storage.sync.get({ port: 2357 }, items => attachDebugger(tab, items.port));
 });
 
-function DebuggerAgent(tab, port) {
-    this.pendingMessages = [];
-    this.connection = null;
-    this.tab = null;
-    this.debuggee = { tabId : tab.id };
-    this.attachedToDebugger = false;
-    this.messageBuffer = "";
-    this.port = port;
-    debuggerAgentMap[tab.id] = this;
-}
-DebuggerAgent.MAX_MESSAGE_SIZE = 65534;
-DebuggerAgent.prototype.attach = function() {
-    chrome.debugger.attach(this.debuggee, "1.0", function(callback) {
-        this.attachedToDebugger = true;
-        chrome.debugger.sendCommand(this.debuggee, "Debugger.enable", {}, callback);
-    }.bind(this, this.connectToServer.bind(this)));
-};
-DebuggerAgent.prototype.connectToServer = function() {
-    this.connection = new WebSocket("ws://localhost:" + this.port + "/");
-    this.connection.onmessage = function(event) {
-        var str = event.data;
-        var ctl = str.substring(0, 1);
-        this.messageBuffer += str.substring(1);
-        if (ctl === '.') {
-            this.receiveMessage(JSON.parse(this.messageBuffer));
-            this.messageBuffer = "";
-        }
-    }.bind(this);
-    this.connection.onclose = function(event) {
-        if (this.connection != null) {
-            this.connection = null;
-            this.disconnect();
-        }
-    }.bind(this);
-    this.connection.onopen = function() {
-        for (var i = 0; i < this.pendingMessages.length; ++i) {
-            this.sendMessage(this.pendingMessages[i]);
-        }
-        this.pendingMessages = null;
-    }.bind(this);
-};
-DebuggerAgent.prototype.receiveMessage = function(message) {
-    chrome.debugger.sendCommand(this.debuggee, message.method, message.params, function(response) {
-        if (message.id) {
-            var responseToServer = { id : message.id, result : response,
-                    error : response ? undefined : chrome.runtime.lastError };
-            this.sendMessage(responseToServer);
-        }
-    }.bind(this));
-};
-DebuggerAgent.prototype.sendMessage = function(message) {
-    var str = JSON.stringify(message);
-    while (str.length > DebuggerAgent.MAX_MESSAGE_SIZE) {
-        var part = "," + str.substring(0, DebuggerAgent.MAX_MESSAGE_SIZE);
-        this.connection.send(part);
-        str = str.substring(DebuggerAgent.MAX_MESSAGE_SIZE);
-    }
-    this.connection.send("." + str);
-};
-DebuggerAgent.prototype.disconnect = function() {
-    if (this.connection) {
-        var conn = this.connection;
-        this.connection = null;
-        conn.close();
-    }
-    if (this.attachedToDebugger) {
-        chrome.debugger.detach(this.debuggee);
-        this.attachedToDebugger = false;
-    }
-    if (this.debuggee) {
-        delete debuggerAgentMap[this.debuggee.tabId];
-        this.debuggee = null;
-    }
-};
-
-chrome.debugger.onEvent.addListener(function(source, method, params) {
-    var agent = debuggerAgentMap[source.tabId];
+chrome.debugger.onEvent.addListener((source, method, params) => {
+    const agent = debuggerAgentMap[source.tabId];
     if (!agent) {
         return;
     }
-    var message = { method : method, params : params };
+    const message = { method : method, params : params };
     if (agent.pendingMessages) {
         agent.pendingMessages.push(message);
     } else if (agent.connection) {
         agent.sendMessage(message);
     }
 });
-chrome.debugger.onDetach.addListener(function(source) {
-    var agent = debuggerAgentMap[source.tabId];
+chrome.debugger.onDetach.addListener((source) => {
+    const agent = debuggerAgentMap[source.tabId];
     if (agent) {
         agent.attachedToDebugger = false;
         agent.disconnect();
     }
 });
 
-chrome.runtime.onMessage.addListener(function(message, sender, callback) {
+chrome.runtime.onMessage.addListener((message, sender) => {
     if (message.command === "debug") {
-        new DebuggerAgent(sender.tab, message.port).attach();
+        attachDebugger(sender.tab, message.port);
     }
-});
\ No newline at end of file
+});
+
+function attachDebugger(tab, port) {
+    const existingAgent = debuggerAgentMap[tab.id];
+    if (!existingAgent) {
+        new DebuggerAgent(tab, port).attach();
+    } else if (existingAgent.port !== port) {
+        existingAgent.disconnect(() => {
+            new DebuggerAgent(tab, port).attach();
+        });
+    }
+}
\ No newline at end of file
diff --git a/tools/chrome-rdp/src/main/js/chrome/options.js b/tools/chrome-rdp/src/main/js/chrome/options.js
index e2b211e31..63f5ec091 100644
--- a/tools/chrome-rdp/src/main/js/chrome/options.js
+++ b/tools/chrome-rdp/src/main/js/chrome/options.js
@@ -15,7 +15,7 @@
  */
 
 function saveOptions() {
-    var port = document.getElementById("port").value;
+    const port = document.getElementById("port").value;
     chrome.storage.sync.set({
         port: port !== "" ? parseInt(port) : 2357,
     });
@@ -24,7 +24,7 @@ function saveOptions() {
 function loadOptions() {
     chrome.storage.sync.get({
         port: 2357,
-    }, function(items) {
+    }, (items) => {
         document.getElementById("port").value = items.port;
     });
 }