Refactor Source to take the system cache as a parameter.

utils/pub/pub.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * The main entrypoint for the pub command line application.
  */
 #library('pub');
 
 #import('../../lib/args/args.dart');
@@ skipping 51 matching lines @@
     printVersion();
     return;
   }
 
   if (globalOptions['help'] || globalOptions.rest.isEmpty()) {
     printUsage(parser, commands);
     return;
   }
 
   var cache = new SystemCache(globalOptions['cachedir']);
-  cache.sources.register(new SdkSource(globalOptions['sdkdir']));
-  cache.sources.register(new GitSource());
-  cache.sources.register(new RepoSource());
+  cache.register(new SdkSource(globalOptions['sdkdir']));
+  cache.register(new GitSource());
+  cache.register(new RepoSource());
   // TODO(nweiz): Make 'repo' the default once pub.dartlang.org exists
   cache.sources.setDefault('sdk');
 
   // Select the command.
   var command = commands[globalOptions.rest[0]];
   if (command == null) {
     printError('Unknown command "${globalOptions.rest[0]}".');
     printError('Run "pub help" to see available commands.');
     exit(64); // See http://www.freebsd.org/cgi/man.cgi?query=sysexits.
     return;
@@ skipping 92 matching lines @@
     future.handleException((e) => handleError(e, future.stackTrace));
   }
 
   /**
    * Override this to perform the specific command. Return a future that
    * completes when the command is done or fails if the command fails. If the
    * command is synchronous, it may return `null`.
    */
   abstract Future onRun();
 }