DevTools: add bindings tests to fixate shadowDOM behavior.

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

 var initialize_BindingsTest = function() {
 
 InspectorTest.preloadModule("sources");
 
 InspectorTest.dumpWorkspace = function(previousSnapshot) {
     var uiSourceCodes = Workspace.workspace.uiSourceCodes().slice();
     var urls = uiSourceCodes.map(code => code.url());
     urls = urls.map(url => {
         if (!url.startsWith('debugger://'))
             return url;
@@ skipping 67 matching lines @@
         evalSource += '//# sourceURL=' + evalSourceURL;
     return InspectorTest.evaluateInPageAsync(evalSource);
 
     function navigateFrame(frameId, url) {
         var frame = document.getElementById(frameId);
         frame.src = url;
         return new Promise(x => frame.onload = x);
     }
 }
 
+InspectorTest.attachShadowDOM = function(id, templateSelector, evalSourceURL) {
+    var evalSource = `(${createShadowDOM.toString()})('${id}', '${templateSelector}')`;
+    if (evalSourceURL)
+        evalSource += '//# sourceURL=' + evalSourceURL;
+    return InspectorTest.evaluateInPagePromise(evalSource);
+
+    function createShadowDOM(id, templateSelector) {
+        var shadowHost = document.createElement('div');
+        shadowHost.setAttribute('id', id);
+        let shadowRoot = shadowHost.attachShadow({mode: 'open'});
+        var t = document.querySelector(templateSelector);
+        var instance = t.content.cloneNode(true);
+        shadowRoot.appendChild(instance);
+        document.body.appendChild(shadowHost);
+    }
+}
+
+InspectorTest.detachShadowDOM = function(id, evalSourceURL) {
+    var evalSource = `(${removeShadowDOM.toString()})('${id}')`;
+    if (evalSourceURL)
+        evalSource += '//# sourceURL=' + evalSourceURL;
+    return InspectorTest.evaluateInPagePromise(evalSource);
+
+    function removeShadowDOM(id) {
+        document.querySelector('#' + id).remove();
+    }
+}
+
+InspectorTest.waitForStyleSheetRemoved = function(urlSuffix) {
+    var fulfill;
+    var promise = new Promise(x => fulfill = x);
+    InspectorTest.cssModel.addEventListener(SDK.CSSModel.Events.StyleSheetRemoved, onStyleSheetRemoved);
+    return promise;
+
+    function onStyleSheetRemoved(event) {
+        var styleSheetHeader = event.data;
+        if (!styleSheetHeader.resourceURL().endsWith(urlSuffix))
+            return;
+        InspectorTest.cssModel.removeEventListener(SDK.CSSModel.Events.StyleSheetRemoved, onStyleSheetRemoved);
+        fulfill();
+    }
+}
+
 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;
 }
 
 
 }