Devtools: Create layout editor experiment

Source/core/inspector/InspectorDOMAgent.cpp

Index: Source/core/inspector/InspectorDOMAgent.cpp
diff --git a/Source/core/inspector/InspectorDOMAgent.cpp b/Source/core/inspector/InspectorDOMAgent.cpp
index a16bb309a89066ab8a27e3a215f9b64953b9debe..ef36d892bfd710fe66ea72242a0fb6e85fdeb7cb 100644
--- a/Source/core/inspector/InspectorDOMAgent.cpp
+++ b/Source/core/inspector/InspectorDOMAgent.cpp
@@ -1241,6 +1241,9 @@ PassOwnPtr<InspectorHighlightConfig> InspectorDOMAgent::highlightConfigFromInspe
     bool showExtensionLines = false; // Default: false (do not show extension lines).
     highlightInspectorObject->getBoolean("showExtensionLines", &showExtensionLines);
     highlightConfig->showExtensionLines = showExtensionLines;
+    bool showLayoutEditor = false;
+    highlightInspectorObject->getBoolean("showLayoutEditor", &showLayoutEditor);
+    highlightConfig->showLayoutEditor = showLayoutEditor;
     highlightConfig->content = parseConfigColor("contentColor", highlightInspectorObject);
     highlightConfig->contentOutline = parseConfigColor("contentOutlineColor", highlightInspectorObject);
     highlightConfig->padding = parseConfigColor("paddingColor", highlightInspectorObject);