Add interfaces for a new compiler API.

tests/compiler/dart2js/analyze_helper.dart

Index: tests/compiler/dart2js/analyze_helper.dart
diff --git a/tests/compiler/dart2js/analyze_helper.dart b/tests/compiler/dart2js/analyze_helper.dart
index b901595cccf5bda555b13a903db8262a0a7554c1..7636eb2d8dcc2ec52c2d8320d2eb10fed6c9a12a 100644
--- a/tests/compiler/dart2js/analyze_helper.dart
+++ b/tests/compiler/dart2js/analyze_helper.dart
@@ -95,8 +95,9 @@ class CollectingDiagnosticHandler extends FormattingDiagnosticHandler {
     return false;
   }
 
-  void diagnosticHandler(Uri uri, int begin, int end, String message,
-                         api.Diagnostic kind) {
+  @override
+  void report(Uri uri, int begin, int end, String message,
+              api.Diagnostic kind) {
     if (kind == api.Diagnostic.WARNING) {
       if (checkWhiteList(uri, message)) {
         // Suppress whitelisted warnings.
@@ -125,7 +126,7 @@ class CollectingDiagnosticHandler extends FormattingDiagnosticHandler {
       return;
     }
     lastWasWhitelisted = false;
-    super.diagnosticHandler(uri, begin, end, message, kind);
+    super.report(uri, begin, end, message, kind);
   }
 }
 
@@ -158,10 +159,11 @@ Future analyze(List<Uri> uriList,
     '--show-package-warnings'];
   if (analyzeAll) options.add('--analyze-all');
   var compiler = new Compiler(
-      provider.readStringFromUri,
+      provider,
       null,
-      handler.diagnosticHandler,
-      libraryRoot, packageRoot,
+      handler,
+      libraryRoot,
+      packageRoot,
       options,
       {});
   String MESSAGE = """