2. Read the platform dill file at startup not for every isolate creation
3. Store the memory representation of kernel program in isolate data so that it is deleted when the isolate is shutdown
R=aam@google.com
Review-Url: https://codereview.chromium.org/2927493002 .
IsolateData contains AppSnapshot which might own some HeapPage-s, so we can't
destroy IsolateData in the Dart_IsolateShutdownCallback, because some thread
running in the isolate (e.g. background compiler) might still touch
thoses pages or objects they host.
We need to delay destruction of AppSnapshot until after the isolate shutdown.
Current API does not allow that, so we introduce a new isolate lifecycle
callback - Dart_IsolateCleanupCallback, which is invoked at the end of the
isolote lifecycle when things like background compiler have been stopped
and no Dart code is supposed to run.
BUG=
R=rmacnak@google.com
Review-Url: https://codereview.chromium.org/2720723005 .
Siva Annamalai