Dart actually expects package: to work. This CL makes package:foo
map to /packages/foo, similar to how Dartium or bin/dart would expect.
This also means overlaying the /gen directory over the actual package
outputs (as consumers of an SDK would expect) as well as adding
an additional /lib indirection for the actual package source as
the Dart pub tool will expect.
This is far from perfect, but it unlocks us actually producing a
sky SDK.
I expect there may be some fallout from this change as I'm sure I
missed some package: uses. We also don't have a general solution
for all /foo/bar/baz includes which randomly included parts
of mojo's source directory. Those will need to be updated to use
a package: and deploy_sdk.py taught how to build a package for them.
R=abarth@chromium.org
Review URL: https://codereview.chromium.org/990493002
This does several things:
1. Teaches sky about asynchronous script execution. Previously once all imports
were loaded and the script text was available, we executed a script and assumed
it completed synchronously. We left the parser loop to do so, but that was fine
as the next chunk from the background thread would resume the parser. In this
change scripts now load and execute separately. The "load" step may trigger
further dart import loads which may cause the execution to happen asynchronously
which required teaching both the DartController and the HTMLScriptRunner to
take callbacks to allow HTMLDocumentParser to know to continue parsing after
the Dart script has resolved its imports and executed.
This required re-working some of how the parser executes scripts and I
re-purposed isWaitingForScripts to include "is the parser blocked" where
as before it was limited only to "does the treebuilder have a script", even
though the imports system may have had pending scripts as well.
I made HTMLScriptRunner live only as long as the script it was executing
since it only contained per-script state at this point.
2. Fixed an error reporting bug whereby we would not show errors when "init"
failed to execute, only "main". This required using the dart_mirrors_api.h
which required adding an include path to the core build. :(
3. Made it possible for a single sky file to contain multiple dart <script>
tags. Each <script> is a separate library and executes as
soon as </script> is seen. main or init is called for each. This required
mangling "urls" for these script blocks since Dart unique's libraries by urls.
Before this change it may have been possible to do <import 'foo.sky'> and then
<script>import 'foo.sky'</script> and have it work!?
R=abarth@chromium.org
BUG=
Review URL: https://codereview.chromium.org/938623005
