DevTools: encapsulate presentation model in timeline view.

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

Index: LayoutTests/http/tests/inspector/timeline-test.js
diff --git a/LayoutTests/http/tests/inspector/timeline-test.js b/LayoutTests/http/tests/inspector/timeline-test.js
index 5b11bead145479e9be3580daf9d0b6a90869ce46..fc65a60b7867aba46db3d991f295304e3df5353c 100644
--- a/LayoutTests/http/tests/inspector/timeline-test.js
+++ b/LayoutTests/http/tests/inspector/timeline-test.js
@@ -34,6 +34,11 @@ InspectorTest.timelinePresentationModel = function()
     return WebInspector.panels.timeline._currentViews[0]._presentationModel;
 }
 
+InspectorTest.timelineModel = function()
+{
+    return WebInspector.panels.timeline._model;
+}
+
 InspectorTest.startTimeline = function(callback)
 {
     InspectorTest._timelineRecords = [];
@@ -128,7 +133,7 @@ InspectorTest.printTimelineRecords = function(typeName, formatter)
 
 InspectorTest.printTimestampRecords = function(typeName, formatter)
 {
-    InspectorTest.innerPrintTimelineRecords(InspectorTest.timelinePresentationModel().eventDividerRecords(), typeName, formatter);
+    InspectorTest.innerPrintTimelineRecords(InspectorTest.timelineModel().eventDividerRecords(), typeName, formatter);
 };
 
 InspectorTest.innerPrintTimelineRecords = function(records, typeName, formatter)