An initial sketch of an alternate element model

This is an attempt to see what the element model might look like if we
made the change I outlined earlier. The goal is to see whether the
changes would be positive or negative from an API perspective.

I have removed comments and any overrides for the sake of brevity.

I added a few comments in places where I thought we might want to
discuss additional changes to the current API. If we're going to make a
breaking change it seems reasonable to consider other possible changes.

Change-Id: I41adfc43e4d8781451723be4433dffc36fb3d47a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/368440
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

https://dart.googlesource.com/sdk/+/a80097b863c6e649d94b1808952c652d46e39550

DEPS

diff --git a/DEPS b/DEPS
index 9cdd40e..182e973 100644
--- a/DEPS
+++ b/DEPS
@@ -282,7 +282,7 @@
 
   'engine/src/flutter': Var('flutter_git') + '/mirrors/engine' + '@' + 'b9104439e31a177f54bc26d777b5abc78f4c292b',
 
-  'engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + '9e0acbc52b49ea7404917b55fa717034127be3da',
+  'engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + 'a80097b863c6e649d94b1808952c652d46e39550',
 
   'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '660694cb1765d82f00aad45b75e819901207b1d3',
 

commits.json

diff --git a/commits.json b/commits.json
index 4f3408e..93e4ace 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "engine/src/flutter":"b9104439e31a177f54bc26d777b5abc78f4c292b",
-  "engine/src/flutter/third_party/dart":"9e0acbc52b49ea7404917b55fa717034127be3da",
+  "engine/src/flutter/third_party/dart":"a80097b863c6e649d94b1808952c652d46e39550",
   "flutter":"660694cb1765d82f00aad45b75e819901207b1d3"
 }
\ No newline at end of file