Add context information to driver and add hooks for plugin management

pkg/analyzer/lib/src/context/builder.dart

 // Copyright (c) 2016, 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.
 
 library analyzer.src.context.context_builder;
 
 import 'dart:collection';
 import 'dart:core';
 
+import 'package:analyzer/context/context_root.dart';
 import 'package:analyzer/context/declared_variables.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/plugin/resolver_provider.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/command_line/arguments.dart'
     show
         applyAnalysisOptionFlags,
         bazelAnalysisOptionsPath,
         flutterAnalysisOptionsPath;
@@ skipping 130 matching lines @@
     context.name = path;
     //_processAnalysisOptions(context, optionMap);
     declareVariables(context);
     return context;
   }
 
   /**
    * Return an analysis driver that is configured correctly to analyze code in
    * the directory with the given [path].
    */
-  AnalysisDriver buildDriver(String path) {
+  AnalysisDriver buildDriver(ContextRoot contextRoot) {
+    String path = contextRoot.root;
     AnalysisOptions options = getAnalysisOptions(path);
     //_processAnalysisOptions(context, optionMap);
     final sf = createSourceFactory(path, options);
     AnalysisDriver driver = new AnalysisDriver(
         analysisDriverScheduler,
         performanceLog,
         resourceProvider,
         byteStore,
         fileContentOverlay,
-        path,
+        contextRoot,
         sf,
         options);
     // temporary plugin support:
     if (onCreateAnalysisDriver != null) {
       onCreateAnalysisDriver(driver, analysisDriverScheduler, performanceLog,
           resourceProvider, byteStore, fileContentOverlay, path, sf, options);
     }
     declareVariablesInDriver(driver);
     return driver;
   }
@@ skipping 631 matching lines @@
 
     // Ensure that the path is absolute and normalized.
     if (!context.isAbsolute(path)) {
       throw new ArgumentError('not absolute: $path');
     }
     path = context.normalize(path);
 
     return new _BasicWorkspace._(provider, path, builder);
   }
 }