DevTools: Polish uiSourceCode context menu on sources panel.

Source/devtools/front_end/sources/SourcesPanel.js

Index: Source/devtools/front_end/sources/SourcesPanel.js
diff --git a/Source/devtools/front_end/sources/SourcesPanel.js b/Source/devtools/front_end/sources/SourcesPanel.js
index 7c3e0d6195c0667a5e5df24ee7913f140e0b08a7..8e1bc0c47675f099e55b843d3624b6e930f68011 100644
--- a/Source/devtools/front_end/sources/SourcesPanel.js
+++ b/Source/devtools/front_end/sources/SourcesPanel.js
@@ -888,7 +888,9 @@ WebInspector.SourcesPanel.prototype = {
             return;
 
         var uiSourceCode = /** @type {!WebInspector.UISourceCode} */ (target);
-        contextMenu.appendItem(WebInspector.UIString(WebInspector.useLowerCaseMenuTitles() ? "Local modifications\u2026" : "Local Modifications\u2026"), this._showLocalHistory.bind(this, uiSourceCode));
+        var project = uiSourceCode.project();
+        if (project.type() !== WebInspector.projectTypes.FileSystem)
+            contextMenu.appendItem(WebInspector.UIString(WebInspector.useLowerCaseMenuTitles() ? "Local modifications\u2026" : "Local Modifications\u2026"), this._showLocalHistory.bind(this, uiSourceCode));
         this._appendUISourceCodeMappingItems(contextMenu, uiSourceCode);
 
         if (!event.target.isSelfOrDescendant(this.editorView.sidebarElement())) {