DevTools: fix front-end compilation following r196255

Source/devtools/front_end/devtools.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(window) {
 
 // DevToolsAPI ----------------------------------------------------------------
 
 /**
  * @constructor
@@ skipping 786 matching lines @@
                  */
                 getFloatValue: function() { return this.__paddingLeft; },
                 __paddingLeft: parseFloat(this.paddingLeft)
             };
         }
         throw new Error("getPropertyCSSValue is undefined");
     }
 
     // Support for legacy (<M41) frontends. Remove in M45.
     window.CSSStyleDeclaration.prototype.getPropertyCSSValue = getValue;
-    window.CSSPrimitiveValue = { CSS_PX: "CSS_PX" };
+
+    function CSSPrimitiveValue()
+    {
+    }
+    CSSPrimitiveValue.CSS_PX = 5;
+    window.CSSPrimitiveValue = CSSPrimitiveValue;
 
     // Support for legacy (<M44) frontends. Remove in M48.
     var styleElement = window.document.createElement("style");
     styleElement.type = "text/css";
     styleElement.textContent = "html /deep/ * { min-width: 0; min-height: 0; }";
     window.document.head.appendChild(styleElement);
 }
 
 function windowLoaded()
 {
@@ skipping 29 matching lines @@
     uiTests.testSuiteReady = function(testSuiteConstructor, testBase)
     {
         uiTests._testSuite = testSuiteConstructor(window.domAutomationController);
         uiTests._tryRun();
     };
 
     window.uiTests = uiTests;
 }
 
 })(window);