dart2js: dump info about dependencies added by the enqueuer

pkg/compiler/lib/src/enqueue.dart

 // Copyright (c) 2012, 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 dart2js.enqueue;
 
 import 'dart:collection' show
     Queue;
 import 'dart2jslib.dart' show
     invariant,
@@ skipping 121 matching lines @@
   /// Returns [:true:] if [member] has been processed by this enqueuer.
   bool isProcessed(Element member);
 
   /**
    * Documentation wanted -- johnniwinther
    *
    * Invariant: [element] must be a declaration element.
    */
   void addToWorkList(Element element) {
     assert(invariant(element, element.isDeclaration));
-    internalAddToWorkList(element);
+    if (internalAddToWorkList(element) && compiler.dumpInfo) {
+      // TODO(sigmund): add other missing dependencies (internals, selectors
+      // enqueued after allocations), also enable only for the codegen enqueuer.
+      compiler.dumpInfoTask.registerDependency(
+          compiler.currentElement, element);
+    }
   }
 
   /**
    * Adds [element] to the work list if it has not already been processed.
    *
    * Returns [true] if the element was actually added to the queue.
    */
   bool internalAddToWorkList(Element element);
 
   /// Apply the [worldImpact] of processing [element] to this enqueuer.
@@ skipping 842 matching lines @@
   void processWorkItem(void f(WorkItem work), WorkItem work) {
     f(work);
   }
 }
 
 void removeFromSet(Map<String, Set<Element>> map, Element element) {
   Set<Element> set = map[element.name];
   if (set == null) return;
   set.remove(element);
 }