DevTools: fix 'Failed to write into a temp file' when recording a filmstrip

Source/devtools/front_end/network/NetworkPanel.js

Index: Source/devtools/front_end/network/NetworkPanel.js
diff --git a/Source/devtools/front_end/network/NetworkPanel.js b/Source/devtools/front_end/network/NetworkPanel.js
index dfa0c597444b17460bde9c6cb9a746847e8db65a..c3b04e7339cc88b11478990d2ea3c227c7fc24e3 100644
--- a/Source/devtools/front_end/network/NetworkPanel.js
+++ b/Source/devtools/front_end/network/NetworkPanel.js
@@ -730,7 +730,10 @@ WebInspector.NetworkPanel.FilmStripRecorder.prototype = {
             return;
 
         this._target = WebInspector.targetManager.mainTarget();
-        this._tracingModel = new WebInspector.TracingModel(new WebInspector.TempFileBackingStorage("tracing"));
+        if (this._tracingModel)
+            this._tracingModel.reset();
+        else
+            this._tracingModel = new WebInspector.TracingModel(new WebInspector.TempFileBackingStorage("tracing"));
         this._target.tracingManager.start(this, "-*,disabled-by-default-devtools.screenshot", "");
         this._filmStripView.reset();
         this._filmStripView.setStatusText(WebInspector.UIString("Recording frames..."));