dart2js: add function coverage tracking in dart2js output, dumpinfo, and

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 'common/tasks.dart' show
@@ skipping 110 matching lines @@
     int size = compiler.dumpInfoTask.sizeOf(element);
     String code;
     StringBuffer emittedCode = compiler.dumpInfoTask.codeOf(element);
     if (emittedCode != null) {
       size += emittedCode.length;
       code = emittedCode.toString();
     }
 
     FieldInfo info = new FieldInfo(
         name: element.name,
+        // We use element.hashCode because it is globally unique and it is
+        // available while we are doing codegen.
+        coverageId: '${element.hashCode}',
         type: '${element.type}',
         inferredType: '$inferredType',
         size: size,
         code: code,
         outputUnit: _unitInfoForElement(element));
     _elementToInfo[element] = info;
 
     List<FunctionInfo> nestedClosures = <FunctionInfo>[];
     for (Element closure in element.nestedClosures) {
       Info child = this.process(closure);
@@ skipping 120 matching lines @@
     }
     String inferredReturnType =
         '${compiler.typesTask.getGuaranteedReturnTypeOfElement(element)}';
     String sideEffects = '${compiler.world.getSideEffectsOfElement(element)}';
 
     int inlinedCount = compiler.dumpInfoTask.inlineCount[element];
     if (inlinedCount == null) inlinedCount = 0;
 
     FunctionInfo info = new FunctionInfo(
         name: name,
+        // We use element.hashCode because it is globally unique and it is
+        // available while we are doing codegen.
+        coverageId: '${element.hashCode}',
         modifiers: modifiers,
         size: size,
         returnType: returnType,
         inferredReturnType: inferredReturnType,
         parameters: parameters,
         sideEffects: sideEffects,
         inlinedCount: inlinedCount,
         code: code,
         type: element.type.toString(),
         outputUnit: _unitInfoForElement(element));
@@ skipping 251 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"
     });
   }
 }