DevTools: Don't show CSS variables in ComputedStyleWidget unless showing all

third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js

Index: third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js
diff --git a/third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js b/third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js
index 6bdf6b930ef2b72d23f2d07daa137f65d76b983d..36817d691339160abfc7f9ed0878cece8d7cda4a 100644
--- a/third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js
+++ b/third_party/WebKit/Source/devtools/front_end/elements/ComputedStyleWidget.js
@@ -158,6 +158,8 @@ Elements.ComputedStyleWidget = class extends UI.ThrottledWidget {
       var inherited = !inhertiedProperties.has(canonicalName);
       if (!showInherited && inherited && !(propertyName in this._alwaysShowComputedProperties))
         continue;
+      if (!showInherited && propertyName.startsWith('--'))
+        continue;
       if (propertyName !== canonicalName && propertyValue === nodeStyle.computedStyle.get(canonicalName))
         continue;