DevTools: add tests to fixate sourcemap bindings behavior

third_party/WebKit/LayoutTests/http/tests/inspector/bindings/bindings-test.js

 var initialize_BindingsTest = function() {
 
 InspectorTest.preloadModule("sources");
 
 InspectorTest.dumpWorkspace = function() {
     var uiSourceCodes = Workspace.workspace.uiSourceCodes().slice();
     var urls = uiSourceCodes.map(code => code.url());
     urls = urls.map(url => {
         if (!url.startsWith('debugger://'))
             return url;
@@ skipping 44 matching lines @@
         var frame = document.getElementById(frameId);
         frame.src = url;
         return new Promise(x => frame.onload = x);
     }
 }
 
 InspectorTest.markStep = function(title) {
     InspectorTest.addResult('\nRunning: ' + title);
 }
 
+InspectorTest.addSniffer(Bindings.CompilerScriptMapping.prototype, "_sourceMapAttachedForTest", onSourceMap, true);
+InspectorTest.addSniffer(Bindings.SASSSourceMapping.prototype, "_sourceMapAttachedForTest", onSourceMap, true);
+var sourceMapCallbacks = new Map();
+function onSourceMap(sourceMap) {
+    for (var urlSuffix of sourceMapCallbacks.keys()) {
+        if (sourceMap.url().endsWith(urlSuffix)) {
+            var callback = sourceMapCallbacks.get(urlSuffix);
+            callback.call(null);
+            sourceMapCallbacks.delete(urlSuffix);
+        }
+    }
 }
 
+InspectorTest.waitForSourceMap = function(sourceMapURLSuffix) {
+    var fulfill;
+    var promise = new Promise(x => fulfill = x);
+    sourceMapCallbacks.set(sourceMapURLSuffix, fulfill);
+    return promise;
+}
+
+
+}
+