Add ServiceWorkerErrorMessage to ServiceWorker DevTool's protocol.

Source/devtools/front_end/sdk/ServiceWorkerManager.js

Index: Source/devtools/front_end/sdk/ServiceWorkerManager.js
diff --git a/Source/devtools/front_end/sdk/ServiceWorkerManager.js b/Source/devtools/front_end/sdk/ServiceWorkerManager.js
index bc5ba4b78b38036c122e512d3f37302cbc9bf584..0fb04a9f2448672e798ec7ffb30c945702135c6b 100644
--- a/Source/devtools/front_end/sdk/ServiceWorkerManager.js
+++ b/Source/devtools/front_end/sdk/ServiceWorkerManager.js
@@ -369,6 +369,15 @@ WebInspector.ServiceWorkerDispatcher.prototype = {
     workerVersionUpdated: function(versions)
     {
         this._manager._workerVersionUpdated(versions);
+    },
+
+    /**
+     * @override
+     * @param {!ServiceWorkerAgent.ServiceWorkerErrorMessage} errorMessage
+     */
+    workerErrorReported: function(errorMessage)
+    {
+        // FIXME: Implement this.
     }
 }