Added uri field to UISourceCode. Debugger and LiveEdit uiSourceCodes are now created through WorkspaceProviders (not projects yet though) which are responsible for unique uri generation. Extracted generic content provider based WorkspaceProvider functionality and url-to-uri conversion logic to ContentProviderWorkspaceProvider class.
Created attachment 180795 [details] Patch
Committed r138536: <http://trac.webkit.org/changeset/138536>