DevTools: introduce CSS.setStyleText, we'll migrate setPropertyText to it later.

LayoutTests/http/tests/inspector-protocol/css-protocol-test.js

 function initialize_cssTest()
 {
 
 InspectorTest.dumpStyleSheetText = function(styleSheetId, callback)
 {
     InspectorTest.sendCommandOrDie("CSS.getStyleSheetText", { styleSheetId: styleSheetId }, onStyleSheetText);
     function onStyleSheetText(result)
     {
         InspectorTest.log("==== Style sheet text ====");
         InspectorTest.log(result.text);
@@ skipping 21 matching lines @@
             InspectorTest.completeTest();
             return;
         }
         InspectorTest.log("Expected protocol error: " + message.error.message);
         callback();
     }
 }
 
 InspectorTest.setPropertyText = updateStyleSheetRange.bind(null, "CSS.setPropertyText");
 InspectorTest.setRuleSelector = updateStyleSheetRange.bind(null, "CSS.setRuleSelector");
+InspectorTest.setStyleText = updateStyleSheetRange.bind(null, "CSS.setStyleText");
 InspectorTest.setMediaText = updateStyleSheetRange.bind(null, "CSS.setMediaText");
 InspectorTest.addRule = updateStyleSheetRange.bind(null, "CSS.addRule");
 
 InspectorTest.requestMainFrameId = function(callback)
 {
     InspectorTest.sendCommandOrDie("Page.enable", {}, pageEnabled);
 
     function pageEnabled()
     {
         InspectorTest.sendCommandOrDie("Page.getResourceTree", {}, resourceTreeLoaded);
@@ skipping 92 matching lines @@
 {
     InspectorTest.requestNodeId(documentNodeId, selector, nodeIdLoaded);
 
     function nodeIdLoaded(nodeId)
     {
         InspectorTest.loadAndDumpMatchingRulesForNode(nodeId, callback);
     }
 }
 
 }