Dart2js option to dump info about compilation

sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart
index 60db17c8d4dfe5e3b2b4b2d3be9cde9a4d05833d..581883f11076dca710bb1a5f1691ae7d9b26d0af 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart
@@ -1177,6 +1177,7 @@ mainBuffer.add(r'''
 
       jsAst.ObjectInitializer initializers =
           descriptor.toObjectInitializer();
+      int sizeBefore = outputBuffers[outputUnit].length;

[ahe, 2013/12/02 15:20:26]

I think you should cache the value outputBuffers[outputUnit] in a local
variable.

       outputBuffers[outputUnit]
           ..write('["${library.getLibraryName()}",$_')
           ..write('"${uri}",$_')
@@ -1188,6 +1189,9 @@ mainBuffer.add(r'''
           ..write(jsAst.prettyPrint(initializers, compiler))
           ..write(library == compiler.mainApp ? ',${n}1' : "")
           ..write('],$n');
+      int sizeAfter =  outputBuffers[outputUnit].length;
+      compiler.dumpInfoTask.codeSizeCounter

[ahe, 2013/12/02 15:20:26]

This needs to be an abstract operation on dumpInfoTask, something like:

compiler.dumpInfoTask.recordSize(library, sizeAfter - sizeBefore);

+          .countCode(library, sizeAfter - sizeBefore);
     }
   }