dart2dart Preproces placeholders instead of renaming them lazily,

lib/compiler/implementation/dart_backend/renamer.dart

Index: lib/compiler/implementation/dart_backend/renamer.dart
diff --git a/lib/compiler/implementation/dart_backend/renamer.dart b/lib/compiler/implementation/dart_backend/renamer.dart
index a2036d532d5fdce56d836573cb9410a66edbaace..ac4a1f644613b34541f2c99286e4c13d6338626a 100644
--- a/lib/compiler/implementation/dart_backend/renamer.dart
+++ b/lib/compiler/implementation/dart_backend/renamer.dart
@@ -8,26 +8,57 @@
  */
 class ConflictingRenamer {
   final Compiler compiler;
+  final PlaceholderCollector placeholderCollector;
   final Map<LibraryElement, Map<String, String>> renamed;
   final Set<String> usedTopLevelIdentifiers;
   final Map<LibraryElement, String> imports;
-  final Map<Node, Placeholder> placeholders;
+  final Map<Node, String> renames;
   int privateNameCounter = 0;
 
-  ConflictingRenamer(this.compiler, this.placeholders) :
+  ConflictingRenamer(this.compiler, this.placeholderCollector) :
       renamed = new Map<LibraryElement, Map<String, String>>(),
       usedTopLevelIdentifiers = new Set<String>(),
-      imports = new Map<LibraryElement, String>() {
+      imports = new Map<LibraryElement, String>(),
+      renames = new Map<Node, String>() {
     // Rename main() right now so that nobody takes its place.
     renameElement(compiler.mainApp.find(Compiler.MAIN));
+
+    // Process local placeholders.
+    placeholderCollector.localPlaceholders.forEach(
+        (Element element, Map<Node, LocalPlaceholder> localPlaceholders) {
+          localPlaceholders.forEach((Node node, LocalPlaceholder placeholder) {
+            // TODO(smok): Check for conflicts with class fields and take usages
+            // into account.
+            renames[node] = placeholder.identifier;
+          });
+        });
+    // Process element placeholders.
+    renamePlaceholders(placeholderCollector.elementPlaceholders,
+        (ElementPlaceholder placeholder) => renameElement(placeholder.element));
+    // Process null placeholders.
+    renamePlaceholders(placeholderCollector.nullPlaceholders,
+        (NullPlaceholder placeholder) => '');
+    // Process private placeholders.
+    renamePlaceholders(placeholderCollector.privatePlaceholders,
+        (PrivatePlaceholder placeholder) =>
+            renamePrivateIdentifier(placeholder.library,
+                placeholder.node.source.slowToString()));
+    // Process unresolved placeholders.
+    renamePlaceholders(placeholderCollector.unresolvedPlaceholders,
+        (UnresolvedPlaceholder placeholder) =>
+            generateUniqueName('Unresolved'));
   }
 
-  // Renamer implementation.
-  String rename(Node node) {
-    Placeholder placeholder = placeholders[node];
-    return (placeholder !== null) ? placeholder.rename(this) : null;
+  void renamePlaceholders(Map<Node, Placeholder> placeholders,
+      String rename(Placeholder placeholder)) {
+    placeholders.forEach((Node node, Placeholder placeholder) {
+      renames[node] = rename(placeholder);
+    });
   }
 
+  // Renamer implementation.
+  String rename(Node node) => renames[node];
+
   String getName(LibraryElement library, String originalName, renamer) =>
       renamed.putIfAbsent(library, () => <String>{})
           .putIfAbsent(originalName, renamer);
@@ -41,11 +72,6 @@ class ConflictingRenamer {
     return name;
   }
 
-  // TODO(smok): Check for conflicts with class fields and take usages
-  // into account.
-  String renameLocalIdentifier(FunctionElement scope, String identifier) =>
-      identifier;
-
   String renameElement(Element element) {
     assert(element.isTopLevel());
     // TODO(smok): Make sure that the new name does not conflict with existing