Migrate DDC to the new analysis driver.

pkg/dev_compiler/web/web_command.dart

Index: pkg/dev_compiler/web/web_command.dart
diff --git a/pkg/dev_compiler/web/web_command.dart b/pkg/dev_compiler/web/web_command.dart
index 00da902503a2bea26c8ad7c2c1b1c46e2ea785ae..32ef21c020d415a511aadcce1e76312fb249ed9f 100644
--- a/pkg/dev_compiler/web/web_command.dart
+++ b/pkg/dev_compiler/web/web_command.dart
@@ -19,7 +19,6 @@ import 'package:analyzer/dart/element/element.dart'
 import 'package:analyzer/file_system/file_system.dart' show ResourceUriResolver;
 import 'package:analyzer/file_system/memory_file_system.dart'
     show MemoryResourceProvider;
-import 'package:analyzer/src/context/context.dart' show AnalysisContextImpl;
 import 'package:analyzer/src/summary/idl.dart' show PackageBundle;
 import 'package:analyzer/src/summary/package_bundle_reader.dart'
     show SummaryDataStore, InSummaryUriResolver, InSummarySource;
@@ -168,8 +167,6 @@ class WebCompileCommand extends Command {
         resourceProvider: resourceProvider,
         summaryData: summaryDataStore);
 
-    var context = compiler.context as AnalysisContextImpl;
-
     var compilerOptions = new CompilerOptions.fromArguments(argResults);
 
     var resolveFn = (String url) {
@@ -232,7 +229,7 @@ class WebCompileCommand extends Command {
     };
 
     CompileModule compileFn = (String imports, String body, String libraryName,
-        String existingLibrary, String fileName) {
+        String existingLibrary, String fileName) async {
       // Instead of returning a single function, return a pair of functions.
       // Create a new virtual File that contains the given Dart source.
       String sourceCode;
@@ -242,12 +239,13 @@ class WebCompileCommand extends Command {
         var dir = path.dirname(existingLibrary);
         // Need to pull in all the imports from the existing library and
         // re-export all privates as privates in this library.
-        var source = context.sourceFactory.forUri(existingLibrary);
+        var source = compiler.driver.sourceFactory.forUri(existingLibrary);
         if (source == null) {
           throw "Unable to load source for library $existingLibrary";
         }
 
-        LibraryElement libraryElement = context.computeLibraryElement(source);
+        var unitResult = await compiler.driver.getUnitElement(source.fullName);
+        LibraryElement libraryElement = unitResult.element.library;
         if (libraryElement == null) {
           throw "Unable to get library element.";
         }
@@ -300,7 +298,7 @@ class WebCompileCommand extends Command {
 
       var unit = new BuildUnit(libraryName, "", [fileName], _moduleForLibrary);
 
-      JSModuleFile module = compiler.compile(unit, compilerOptions);
+      JSModuleFile module = await compiler.compile(unit, compilerOptions);
 
       var moduleCode = '';
       if (module.isValid) {