Created PreferenceContentProvider and tests.  Write will cause an onChange event to occur.
Releasing 0.16
Review fix and test update.
Merge pull request #3496 from dart-lang/umop-preferences-PreferenceStore_provider

Created PreferenceContentProvider
fix navigation when deleting project
address comments
Merge pull request #3508 from keertip/nav

fix navigation when deleting project
fix a checked mode issues with preferences.dart
Bumped Chrome Platform Analytics to 1.5.2
Merge pull request #3509 from devoncarew/devoncarew_prefs_types

fix a checked mode issues with preferences.dart
Fix "JS Polymer element" template
Merge pull request #3512 from ussuri/fix-templates

Fix "JS Polymer element" template
Merge pull request #3510 from emilycodes/bump-chrome-platform-analytics

Bumped Chrome Platform Analytics to 1.5.2
Nicer code structure around promises
Fix: make webview fill up the host regardless of how its geometry was set
Better event names/details for spark-overlay
Enable external sizing of spark-dialog + make dialog's body autosize & autofit `flex` children
Merge pull request #3531 from ussuri/spark-dialog-fixes

spark-dialog fixes
Merge remote-tracking branch 'upstream/master' into cde-polymer-designer