DevTools: get rid of WebInspector.cssModel, use target models instead

Source/devtools/front_end/elements/MetricsSidebarPane.js

Index: Source/devtools/front_end/elements/MetricsSidebarPane.js
diff --git a/Source/devtools/front_end/elements/MetricsSidebarPane.js b/Source/devtools/front_end/elements/MetricsSidebarPane.js
index a5a9d95fc0cea8793d5f011bb4e3a1954bc6e2f9..0eb4c5783a6884b69b7c2ab1e464959fd159a672 100644
--- a/Source/devtools/front_end/elements/MetricsSidebarPane.js
+++ b/Source/devtools/front_end/elements/MetricsSidebarPane.js
@@ -439,7 +439,7 @@ WebInspector.MetricsSidebarPane.prototype = {
 
         if (computedStyle.getPropertyValue("box-sizing") === "border-box" && (styleProperty === "width" || styleProperty === "height")) {
             if (!userInput.match(/px$/)) {
-                WebInspector.console.addErrorMessage("For elements with box-sizing: border-box, only absolute content area dimensions can be applied", true);
+                WebInspector.console.error("For elements with box-sizing: border-box, only absolute content area dimensions can be applied");
                 return;
             }