Timeline view refactoring (#20)

* improvements to the timeline protocol parsing

* checkpoint

* checkpoint

* finish timeline cleanup

* add tests

* review comments

Author: devoncarew

lib/logging/logging.dart

@@ -87,6 +87,7 @@ class LoggingScreen extends Screen {
     logCountStatus.element.text = '$label events';
   }
 
+  // TODO(devoncarew): Update this url.
   @override
   HelpInfo get helpInfo =>
       new HelpInfo(title: 'logs view docs', url: 'http://www.cheese.com');

lib/memory/memory.dart

@@ -203,6 +203,7 @@ class MemoryScreen extends Screen {
     return memoryTable.element;
   }
 
+  // TODO(devoncarew): Update this url.
   @override
   HelpInfo get helpInfo =>
       new HelpInfo(title: 'memory view docs', url: 'http://www.cheese.com');

lib/performance/performance.dart

@@ -162,6 +162,7 @@ class PerformanceScreen extends Screen {
     }
   }
 
+  // TODO(devoncarew): Update this url.
   @override
   HelpInfo get helpInfo => new HelpInfo(
       title: 'performance view docs', url: 'http://www.cheese.com');