Add measurements and send-metrics to dart2js's info.

lib/info.dart

Index: lib/info.dart
diff --git a/lib/info.dart b/lib/info.dart
index 40cefe2f15c2c9145c4de88994957293afa10f9d..0c07c1bb35034c86a2564647921858f31bb98585 100644
--- a/lib/info.dart
+++ b/lib/info.dart
@@ -5,8 +5,12 @@
 /// Data produced by dart2js when run with the `--dump-info` flag.
 library dart2js_info.info;
 
+import 'src/measurements.dart';
+export 'src/measurements.dart';
+
 /// Common interface to many pieces of information generated by the dart2js
-/// compiler.
+/// compiler that are directly associated with an element (compilation unit,
+/// library, class, function, or field).
 abstract class Info {
   /// An identifier for the kind of information.
   InfoKind get kind;
@@ -369,12 +373,34 @@ class _ParseHelper {
       ..code = json['code']
       ..sideEffects = json['sideEffects']
       ..modifiers = parseModifiers(json['modifiers'])
-      ..closures = json['children'].map(parseId).toList();
+      ..closures = json['children'].map(parseId).toList()
+      ..measurements = parseMeasurements(json['measurements']);
   }
 
   ParameterInfo parseParameter(Map json) =>
       new ParameterInfo(json['name'], json['type'], json['declaredType']);
 
+  Measurements parseMeasurements(Map json) {
+    if (json == null) return null;
+    var uri = json['sourceFile'];
+    var res = new Measurements(uri == null ? null : Uri.parse(uri));
+    for (var key in json.keys) {
+      var value = json[key];
+      if (value == null) continue;
+      if (key == 'entries') {
+        value.forEach((metricName, entries) {
+          var metric = Metric.fromJson(metricName);
+          for (var i = 0; i < entries.length; i += 2) {
+            res.record(metric, entries[i], entries[i + 1]);
+          }
+        });
+      } else {
+        res.counters[Metric.fromJson(key)] = value;
+      }
+    }
+    return res;
+  }
+
   FunctionModifiers parseModifiers(Map<String, bool> json) {
     return new FunctionModifiers(
         isStatic: json['static'] == true,
@@ -422,6 +448,10 @@ class LibraryInfo extends BasicInfo {
   /// Typedefs defined within the library.
   final List<TypedefInfo> typedefs = <TypedefInfo>[];
 
+  // TODO(sigmund): add here a list of parts. That can help us improve how we
+  // encode source-span information in metrics (rather than include the uri on
+  // each function, include an index into this list).
+
   static int _id = 0;
 
   /// Whether there is any information recorded for this library.
@@ -618,6 +648,9 @@ class FunctionInfo extends BasicInfo with CodeInfo {
   /// The actual generated code.
   String code;
 
+  /// Measurements collected for this function.
+  Measurements measurements;
+
   FunctionInfo(
       {String name,
       String coverageId,
@@ -632,7 +665,8 @@ class FunctionInfo extends BasicInfo with CodeInfo {
       this.parameters,
       this.sideEffects,
       this.inlinedCount,
-      this.code})
+      this.code,
+      this.measurements})
       : super(InfoKind.function, _ids++, name, outputUnit, size, coverageId);
 
   FunctionInfo._(String serializedId) : super._fromId(serializedId);
@@ -648,6 +682,7 @@ class FunctionInfo extends BasicInfo with CodeInfo {
       'inlinedCount': inlinedCount,
       'code': code,
       'type': type,
+      'measurements': measurements?.toJson(),
       // Note: version 3.2 of dump-info serializes `uses` in a section called
       // `holding` at the top-level.
     });