dart2js send stats, includes:

pkg/compiler/lib/src/dump_info.dart

 // Copyright (c) 2013, 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 dump_info;
 
 import 'dart:convert'
     show HtmlEscape, JsonEncoder, StringConversionSink, ChunkedConversionSink;
 
 import 'package:dart2js_info/info.dart';
@@ skipping 13 matching lines @@
     TypeMask;
 import 'deferred_load.dart' show
     OutputUnit;
 import 'js_backend/js_backend.dart' show
     JavaScriptBackend;
 import 'js_emitter/full_emitter/emitter.dart' as full show
     Emitter;
 import 'js/js.dart' as jsAst;
 import 'universe/universe.dart' show
     UniverseSelector;
+import 'stats/builder.dart';
 
 class ElementInfoCollector extends BaseElementVisitor<Info, dynamic> {
   final Compiler compiler;
 
   final AllInfo result = new AllInfo();
   final Map<Element, Info> _elementToInfo = <Element, Info>{};
   final Map<ConstantValue, Info> _constantToInfo = <ConstantValue, Info>{};
   final Map<OutputUnit, OutputUnitInfo> _outputToInfo = {};
 
   ElementInfoCollector(this.compiler);
@@ skipping 175 matching lines @@
         classInfo.fields.isEmpty &&
         classInfo.functions.isEmpty) {
       return null;
     }
     result.classes.add(classInfo);
     return classInfo;
   }
 
   FunctionInfo visitFunctionElement(FunctionElement element, _) {
     int size = compiler.dumpInfoTask.sizeOf(element);
+    // TODO(sigmund): consider adding a small info to represent unreachable
+    // code here.
     if (size == 0 && !shouldKeep(element)) return null;
 
     String name = element.name;
     int kind = FunctionInfo.TOP_LEVEL_FUNCTION_KIND;
     var enclosingElement = element.enclosingElement;
     if (enclosingElement.isField ||
         enclosingElement.isFunction ||
         element.isClosure ||
         enclosingElement.isConstructor) {
       kind = FunctionInfo.CLOSURE_FUNCTION_KIND;
@@ skipping 71 matching lines @@
             child.name = "${parent.name}.${child.name}";
           }
           nestedClosures.add(child);
           child.parent = parent;
           size += child.size;
         }
       }
     }
     info.closures = nestedClosures;
     result.functions.add(info);
+    if (const bool.fromEnvironment('send_stats')) {
+      info.measurements = collectSendMeasurements(element, compiler);
+    }
     return info;
   }
 
   OutputUnitInfo _unitInfoForElement(Element element) {
     OutputUnit outputUnit =
       compiler.deferredLoadTask.outputUnitForElement(element);
     return _outputToInfo.putIfAbsent(outputUnit, () {
       // Dump-info currently only works with the full emitter. If another
       // emitter is used it will fail here.
       JavaScriptBackend backend = compiler.backend;
@@ skipping 149 matching lines @@
     List<jsAst.Node> code = _elementToNodes[element];
     if (code == null) return null;
     // Concatenate rendered ASTs.
     StringBuffer sb = new StringBuffer();
     for (jsAst.Node ast in code) {
       sb.writeln(jsAst.prettyPrint(ast, compiler).getText());
     }
     return sb.toString();
   }
 
-  void collectInfo() {
-    infoCollector = new ElementInfoCollector(compiler)..run();
-  }
-
   void dumpInfo() {
     measure(() {
-      if (infoCollector == null) {
-        collectInfo();
-      }
-
+      infoCollector = new ElementInfoCollector(compiler)..run();
       StringBuffer jsonBuffer = new StringBuffer();
       dumpInfoJson(jsonBuffer);
       compiler.outputProvider('', 'info.json')
         ..add(jsonBuffer.toString())
         ..close();
     });
   }
 
   void dumpInfoJson(StringSink buffer) {
     JsonEncoder encoder = const JsonEncoder.withIndent('  ');
@@ skipping 51 matching lines @@
 
     ChunkedConversionSink<Object> sink = encoder.startChunkedConversion(
         new StringConversionSink.fromStringSink(buffer));
     sink.add(result.toJson());
     compiler.reportInfo(NO_LOCATION_SPANNABLE, MessageKind.GENERIC, {
       'text': "View the dumped .info.json file at "
           "https://dart-lang.github.io/dump-info-visualizer"
     });
   }
 }