Reapply class/method/field minification

sdk/lib/_internal/compiler/implementation/js_backend/backend.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 js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 682 matching lines @@
    * TODO(ngeoffray): Use a BitSet instead.
    */
   final Map<ClassElement, ClassElement> interceptedClasses;
 
   List<CompilerTask> get tasks {
     return <CompilerTask>[builder, optimizer, generator, emitter];
   }
 
   final RuntimeTypeInformation rti;
 
-  JavaScriptBackend(Compiler compiler,
-                    bool generateSourceMap,
-                    bool disableEval)
-      : namer = new Namer(compiler),
+  JavaScriptBackend(Compiler compiler, bool generateSourceMap, bool disableEval)
+      : namer = determineNamer(compiler),
         returnInfo = new Map<Element, ReturnInfo>(),
         invalidateAfterCodegen = new List<Element>(),
         interceptors = new Interceptors(compiler),
         usedInterceptors = new Set<Selector>(),
         interceptedElements = new Map<SourceString, Set<Element>>(),
         rti = new RuntimeTypeInformation(compiler),
         specializedGetInterceptors =
             new Map<String, Collection<ClassElement>>(),
         interceptedClasses = new LinkedHashMap<ClassElement, ClassElement>(),
         super(compiler, JAVA_SCRIPT_CONSTANT_SYSTEM) {
     emitter = disableEval
         ? new CodeEmitterNoEvalTask(compiler, namer, generateSourceMap)
         : new CodeEmitterTask(compiler, namer, generateSourceMap);
     builder = new SsaBuilderTask(this);
     optimizer = new SsaOptimizerTask(this);
     generator = new SsaCodeGeneratorTask(this);
     argumentTypes = new ArgumentTypesRegistry(this);
     fieldTypes = new FieldTypesRegistry(this);
   }
 
+  static Namer determineNamer(Compiler compiler) {
+    return compiler.enableMinification ?
+        new MinifyNamer(compiler) :
+        new Namer(compiler);
+  }
+
   bool isInterceptorClass(Element element) {
     if (element == null) return false;
     return interceptedClasses.containsKey(element);
   }
 
   void addInterceptedSelector(Selector selector) {
     usedInterceptors.add(selector);
   }
 
   /**
@@ skipping 391 matching lines @@
     print("Inferred return types:");
     print("----------------------");
     dumpReturnTypes();
     print("");
     print("Inferred field types:");
     print("------------------------");
     fieldTypes.dump();
     print("");
   }
 }