--- a/devtools/client/framework/toolbox.js
+++ b/devtools/client/framework/toolbox.js
@@ -1984,18 +1984,18 @@ Toolbox.prototype = {
     });
   },
 
   /**
    * Fired when user just started navigating away to another web page.
    */
   async _onWillNavigate() {
     let toolId = this.currentToolId;
-    // For now, only inspector fires "reloaded" event
-    if (toolId != "inspector") {
+    // For now, only inspector and webconsole fires "reloaded" event
+    if (toolId != "inspector" && toolId != "webconsole") {
       return;
     }
 
     let start = this.win.performance.now();
     let panel = this.getPanel(toolId);
     // Ignore the timing if the panel is still loading
     if (!panel) {
       return;

--- a/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js
+++ b/devtools/client/webconsole/new-console-output/new-console-output-wrapper.js
@@ -298,16 +298,20 @@ NewConsoleOutputWrapper.prototype = {
         // the backend has been received. This is based on
         // 'FirefoxDataProvider.isQueuePayloadReady', see more
         // comments in that method.
         // (netmonitor/src/connector/firefox-data-provider).
         // This event might be utilized in tests to find the right
         // time when to finish.
         this.jsterm.hud.emit("network-request-payload-ready");
       }
+      if (this.throttleCallback) {
+        this.throttleCallback();
+        delete this.throttleCallback;
+      }
     }, 50);
   },
 
   // Should be used for test purpose only.
   getStore: function () {
     return store;
   }
 };

--- a/devtools/client/webconsole/new-webconsole.js
+++ b/devtools/client/webconsole/new-webconsole.js
@@ -303,32 +303,56 @@ NewWebConsoleFrame.prototype = {
    *
    * @param string event
    *        Event name.
    * @param object packet
    *        Notification packet received from the server.
    */
   handleTabNavigated: function (event, packet) {
     if (event == "will-navigate") {
+      this._navigationStart = this.window.performance.now();
       if (this.persistLog) {
         // Add a _type to hit convertCachedPacket.
         packet._type = true;
         this.newConsoleOutput.dispatchMessageAdd(packet);
       } else {
         this.clearOutput(false);
       }
     }
 
     if (packet.url) {
       this.onLocationChange(packet.url, packet.title);
     }
 
     if (event == "navigate" && !packet.nativeConsoleAPI) {
       this.logWarningAboutReplacedAPI();
     }
+
+    if (event == "navigate") {
+      let timeout = this.newConsoleOutput.throttledDispatchTimeout;
+      if (timeout) {
+        this.newConsoleOutput.throttleCallback = () => {
+          let delay = this.window.performance.now() - this._navigationStart;
+
+          // TODO - REMOVE DEBUG CODE
+          let window = this.window;
+          let canvas = window.document.createElementNS("http://www.w3.org/1999/xhtml", "html:canvas");
+          let context = canvas.getContext("2d");
+          canvas.width = window.innerWidth;
+          canvas.height = window.innerHeight;
+          context.drawWindow(window, 0, 0, canvas.width, canvas.height, "rgb(255, 255, 255)");
+          dump(">> "+canvas.toDataURL()+"\n");
+          // TODO - REMOVE DEBUG CODE
+
+          this.emit("reloaded");
+        };
+      } else {
+        this.emit("reloaded");
+      }
+    }
   },
 
   clearOutput(clearStorage) {
     this.newConsoleOutput.dispatchMessagesClear();
     this.webConsoleClient.clearNetworkRequests();
     if (clearStorage) {
       this.webConsoleClient.clearMessagesCache();
     }

--- a/devtools/client/webconsole/panel.js
+++ b/devtools/client/webconsole/panel.js
@@ -76,16 +76,21 @@ WebConsolePanel.prototype = {
 
         let webConsoleUIWindow = iframe.contentWindow.wrappedJSObject;
         let chromeWindow = iframe.ownerDocument.defaultView;
         return HUDService.openWebConsole(this.target, webConsoleUIWindow,
                                          chromeWindow);
       })
       .then((webConsole) => {
         this.hud = webConsole;
+        // Pipe 'reloaded' event from NewWebConsoleFrame to WebConsolePanel.
+        // These events are listened by the Toolbox.
+        this.hud.ui.on("reloaded", () => {
+          this.emit("reloaded");
+        });
         this._isReady = true;
         this.emit("ready");
         return this;
       }, (reason) => {
         let msg = "WebConsolePanel open failed. " +
                   reason.error + ": " + reason.message;
         dump(msg + "\n");
         console.error(msg, reason);