Roll Dart forward and use the shared vmservice isolate sources + benchmark fixes

BUG=
R=zra@google.com

Review URL: https://codereview.chromium.org/1649823002 .
diff --git a/mojo/tools/data/benchmarks b/mojo/tools/data/benchmarks
index b1eba30..21e8cb5 100644
--- a/mojo/tools/data/benchmarks
+++ b/mojo/tools/data/benchmarks
@@ -15,6 +15,9 @@
         'name': 'accept connection',
         'spec': 'time_between/Dart/initialized/Dart/connected',
       }
+    ],
+    'shell-args': [
+      '--args-for=mojo:dart_content_handler --complete-timeline',
     ]
   },
   {
@@ -26,6 +29,9 @@
         'name': 'initialize',
         'spec': 'time_between/Dart/connecting/Dart/initialized',
       }
+    ],
+    'shell-args': [
+      '--args-for=mojo:dart_content_handler --complete-timeline',
     ]
   },
   {
@@ -43,7 +49,7 @@
       }
     ],
     'shell-args': [
-      '--args-for=mojo:dart_content_handler --disable-observatory',
+      '--args-for=mojo:dart_content_handler --disable-observatory --complete-timeline',
     ]
   },
   {
@@ -61,7 +67,7 @@
       }
     ],
     'shell-args': [
-      '--args-for=mojo:dart_content_handler --run-on-message-loop',
+      '--args-for=mojo:dart_content_handler --run-on-message-loop --complete-timeline',
     ]
   },
   {