This CL makes it possible to run Sky apps offline by introducing new
DartLibraryProvider subclasses, specifically one that can load directly from
the file system. A future CL will expand this functionality to work with asset
bundles as well.
Currently, the only platform that uses this functionality is Linux, which can
now load a simple Sky app without even loading a network stack. Making this
work on other platforms is work for future CLs.
TBR=eseidel@chromium.org
Review URL: https://codereview.chromium.org/1203143004.
This CL makes it possible to build sky_shell on Linux. It doesn't do much, but
it doesn't crash on startup. The goal is to evetually be able to test sky_shell
on the bots and to be able to run the test_sky on Mac.
R=eseidel@chromium.org
Review URL: https://codereview.chromium.org/1202323002.
