Fix some observatory analysis issues.

runtime/observatory/lib/src/app/page.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of app;
 
 final _allocationProfileRepository = new AllocationProfileRepository();
 final _breakpointRepository = new BreakpointRepository();
 final _classRepository = new ClassRepository();
 final _classSampleProfileRepository = new ClassSampleProfileRepository();
@@ skipping 499 matching lines @@
         new ObjectViewElement(
             app.vm,
             obj.isolate,
             obj,
             app.events,
             app.notifications,
             _objectRepository,
             _retainedSizeRepository,
             _reachableSizeRepository,
             _inboundReferencesRepository,
             _retainingPathRepository,

[siva, 2017/06/01 19:26:32]

why remove _objectRepository? The factory constructor of ObjectViewElement is :

  factory ObjectPoolViewElement(
      M.VM vm,
      M.IsolateRef isolate,
      M.ObjectPool pool,
      M.EventRepository events,
      M.NotificationRepository notifications,
      M.ObjectPoolRepository pools,
      M.RetainedSizeRepository retainedSizes,
      M.ReachableSizeRepository reachableSizes,
      M.InboundReferencesRepository references,
      M.RetainingPathRepository retainingPaths,
      M.ObjectRepository objects,
      {RenderingQueue queue}) {

[devoncarew, 2017/06/01 20:11:54]

This is creating a ObjectViewElement (not a ObjectPoolViewElement - created
above). I assume that ObjectViewElement is the object type we want to create
here, but it would be good to have someone familiar with the code to double
check :)

[siva, 2017/06/01 21:28:07]

Ah ok, ObjectPoolViewElement was created above.

-            _objectRepository,
             queue: app.queue)
       ];
     } else if (obj is Sentinel) {
       container.children = [
         new SentinelViewElement(
             app.vm, obj.isolate, obj, app.events, app.notifications,
             queue: app.queue)
       ];
     } else {
       container.children = [
@@ skipping 384 matching lines @@
     element = new TimelinePageElement(app.vm, app.events, app.notifications,
         queue: app.queue);
   }
 
   void _visit(Uri uri) {
     assert(canVisit(uri));
   }
 
   bool canVisit(Uri uri) => uri.path == 'timeline';
 }