Show custom properties in the computed style pane of the inspector.

third_party/WebKit/Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 970 matching lines @@
 
 void InspectorCSSAgent::getComputedStyleForNode(ErrorString* errorString, int nodeId, RefPtr<TypeBuilder::Array<TypeBuilder::CSS::CSSComputedStyleProperty> >& style)
 {
     Node* node = m_domAgent->assertNode(errorString, nodeId);
     if (!node)
         return;
 
     RefPtrWillBeRawPtr<CSSComputedStyleDeclaration> computedStyleInfo = CSSComputedStyleDeclaration::create(node, true);
     RefPtrWillBeRawPtr<InspectorStyle> inspectorStyle = InspectorStyle::create(computedStyleInfo, nullptr, nullptr);
     style = inspectorStyle->buildArrayForComputedStyle();
+
+    if (!RuntimeEnabledFeatures::cssVariablesEnabled())
+        return;
+
+    const HashMap<AtomicString, RefPtr<CSSVariableData>>* variables = computedStyleInfo->getVariables();
+
+    if (variables && !variables->isEmpty()) {
+        for (const auto& it : *variables) {
+            RefPtr<TypeBuilder::CSS::CSSComputedStyleProperty> entry = TypeBuilder::CSS::CSSComputedStyleProperty::create()
+                .setName(it.key)
+                .setValue(it.value->tokenRange().serialize());
+            style->addItem(entry);
+        }
+    }
 }
 
 void InspectorCSSAgent::collectPlatformFontsForLayoutObject(LayoutObject* layoutObject, HashCountedSet<String>* fontStats)
 {
     if (!layoutObject->isText())
         return;
 
     FontCachePurgePreventer preventer;
     LayoutText* layoutText = toLayoutText(layoutObject);
     for (InlineTextBox* box = layoutText->firstTextBox(); box; box = box->nextTextBox()) {
@@ skipping 988 matching lines @@
     visitor->trace(m_documentToCSSStyleSheets);
     visitor->trace(m_invalidatedDocuments);
     visitor->trace(m_nodeToInspectorStyleSheet);
     visitor->trace(m_documentToViaInspectorStyleSheet);
 #endif
     visitor->trace(m_inspectorUserAgentStyleSheet);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink