[DevTools] Turn TracingManager into SDKModel.

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

 function wrapCallFunctionForTimeline(f)
 {
     var script = document.createElement("script");
     script.textContent = "(" + f.toString() + ")()\n//# sourceURL=wrapCallFunctionForTimeline.js";
     document.body.appendChild(script);
 }
 
 var initialize_Timeline = function() {
 
 InspectorTest.preloadPanel("timeline");
@@ skipping 116 matching lines @@
     tracingModel.tracingComplete();
     var performanceModel = new Timeline.PerformanceModel();
     performanceModel.setTracingModel(tracingModel);
     return performanceModel;
 }
 
 InspectorTest.timelineController = function()
 {
     var performanceModel = new Timeline.PerformanceModel();
     UI.panels.timeline._pendingPerformanceModel = performanceModel;
-    return new Timeline.TimelineController(SDK.targetManager.mainTarget(), performanceModel, UI.panels.timeline);
+    return new Timeline.TimelineController(InspectorTest.tracingManager, performanceModel, UI.panels.timeline);
 }
 
 InspectorTest.runWhenTimelineIsReady = function(callback)
 {
     InspectorTest.addSniffer(UI.panels.timeline, "loadingComplete", () => callback());
 }
 
 InspectorTest.startTimeline = function(callback)
 {
     var panel = UI.panels.timeline;
@@ skipping 297 matching lines @@
 function waitForFrame()
 {
     var callback;
     var promise = new Promise((fulfill) => callback = fulfill);
     if (window.testRunner)
         testRunner.capturePixelsAsyncThen(() => window.requestAnimationFrame(callback));
     else
         window.requestAnimationFrame(callback);
     return promise;
 }