Clean up dump-info and js_backend.

sdk/lib/_internal/compiler/implementation/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,
@@ skipping 58 matching lines @@
         }
       });
       json[mapper.name] = innerMapper;
     }
     return json;
   }
 }
 
 class ElementToJsonVisitor extends ElementVisitor<Map<String, dynamic>> {
   GroupedIdMapper mapper = new GroupedIdMapper();
   Compiler compiler;

[sra1, 2014/08/19 22:05:25]

Can be 'final'.

Make other fields could be final too where appropriate

[Ty Overby (Google), 2014/08/20 17:23:50]

Done.

 
   Map<Element, Map<String, dynamic>> jsonCache = {};
   Map<Element, jsAst.Expression> codeCache;
 
   int programSize;
   DateTime compilationMoment;
   String dart2jsVersion;
   Duration compilationDuration;
   Duration dumpInfoDuration;
 
-  ElementToJsonVisitor(Compiler compiler) {
-    this.compiler = compiler;
+  ElementToJsonVisitor(Compiler compiler)

[sra1, 2014/08/19 22:05:25]

Or ElementToJsonVisitor(this.compiler)

[Ty Overby (Google), 2014/08/20 17:23:50]

Done.

+      :compiler = compiler {

[sigurdm, 2014/08/20 08:37:47]

Nitpicking: space after the colon.

From the style guide:
DO format constructor initialization lists with each field on its own line.
MyClass()
    : firstField = "some value",
      secondField = "another",
      thirdField = "last" {
  // ...
}

[Ty Overby (Google), 2014/08/20 17:23:50]

Acknowledged.

 
     Backend backend = compiler.backend;

[sra1, 2014/08/19 22:05:25]

Peter suggested not doing so much work in the constructor.
You could put all this code in a 'run' method and call

new ElementToJsonVisitor(compiler).run()

[Ty Overby (Google), 2014/08/20 17:23:50]

Done.

     if (backend is JavaScriptBackend) {
       // Add up the sizes of all output-buffers.
       programSize = backend.emitter.outputBuffers.values.fold(0,
           (a, b) => a + b.length);
     } else {
       programSize = compiler.assembledCode.length;
     }
 
-
     compilationMoment = new DateTime.now();
     dart2jsVersion = compiler.hasBuildId ? compiler.buildId : null;
     compilationDuration = compiler.totalCompileTime.elapsed;
 
     for (var library in compiler.libraryLoader.libraries.toList()) {
       library.accept(this);
     }
 
     dumpInfoDuration = new DateTime.now().difference(compilationMoment);
   }
@@ skipping 501 matching lines @@
     };
 
     outJson['program'] = generalProgramInfo;
 
     ChunkedConversionSink<Object> sink =
       encoder.startChunkedConversion(
           new StringConversionSink.fromStringSink(buffer));
     sink.add(outJson);
   }
 }