- Eliminated the excessive prefixing in the renamer of dart2dart.

sdk/lib/_internal/compiler/implementation/dart_backend/renamer.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.
 
 part of dart_backend;
 
 Comparator get _compareNodes =>
     compareBy((n) => n.getBeginToken().charOffset);
 
 typedef String _Renamer(Renamable renamable);
@@ skipping 288 matching lines @@
       (_) => generateUniqueName('Unresolved'));
   renameNodes(placeholderCollector.nullNodes, (_) => '');
   if (cutDeclarationTypes) {
     for (DeclarationTypePlaceholder placeholder in
          placeholderCollector.declarationTypePlaceholders) {
       renames[placeholder.typeNode] = placeholder.requiresVar ? 'var' : '';
     }
   }
 }
 
+/**
+ * Generates mini ID based on index.
+ * In other words, it converts index to visual representation
+ * as if digits are given characters.
+ */
+String generateMiniId(int index) {
+  const String firstCharAlphabet =
+      r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
+  const String otherCharsAlphabet =
+      r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_$';
+  // It's like converting index in decimal to [chars] radix.
+  StringBuffer resultBuilder = new StringBuffer();
+  if (index < firstCharAlphabet.length) return firstCharAlphabet[index];
+  resultBuilder.write(firstCharAlphabet[index % firstCharAlphabet.length]);
+  index ~/= firstCharAlphabet.length;
+  int length = otherCharsAlphabet.length;
+  while (index >= length) {
+    resultBuilder.write(otherCharsAlphabet[index % length]);
+    index ~/= length;
+  }
+  resultBuilder.write(otherCharsAlphabet[index]);
+  return resultBuilder.toString();
+}
+
+
 /** Always tries to return original identifier name unless it is forbidden. */
-String conservativeGenerator(
-    String originalName, bool isForbidden(String name)) {
-  String newName = originalName;
-  while (isForbidden(newName)) {
-    newName = 'p_$newName';
+String conservativeGenerator(String name, bool isForbidden(String name)) {
+  String result = name;
+  int index = 0;
+  while (isForbidden(result)) {
+    result = '${generateMiniId(index++)}_$name';
   }
-  return newName;
+  return result;
 }
 
+
 /** Always tries to generate the most compact identifier. */
 class MinifyingGenerator {
-  static const String firstCharAlphabet =
-      r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
-  static const String otherCharsAlphabet =
-      r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_$';
-  int nextIdIndex;
+  int index = 0;
 
-  MinifyingGenerator() : nextIdIndex = 0;
+  MinifyingGenerator();
 
   String generate(bool isForbidden(String name)) {
-    String newName;
+    String result;
     do {
-      newName = getNextId();
-    } while(isForbidden(newName));
-    return newName;
+      result = generateMiniId(index++);
+    } while(isForbidden(result));
+    return result;
   }
-
-  /**
-   * Generates next mini ID with current index and alphabet.
-   * Advances current index.
-   * In other words, it converts index to visual representation
-   * as if digits are given characters.
-   */
-  String getNextId() {
-    // It's like converting index in decimal to [chars] radix.
-    int index = nextIdIndex++;
-    StringBuffer resultBuilder = new StringBuffer();
-    if (index < firstCharAlphabet.length) return firstCharAlphabet[index];
-    resultBuilder.write(firstCharAlphabet[index % firstCharAlphabet.length]);
-    index ~/= firstCharAlphabet.length;
-    int length = otherCharsAlphabet.length;
-    while (index >= length) {
-      resultBuilder.write(otherCharsAlphabet[index % length]);
-      index ~/= length;
-    }
-    resultBuilder.write(otherCharsAlphabet[index]);
-    return resultBuilder.toString();
-  }
-}
+}