Use common.dart to re-export commonly used entities.

pkg/compiler/lib/src/js_emitter/program_builder/program_builder.dart

 // Copyright (c) 2014, 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.js_emitter.program_builder;
 
-import '../js_emitter.dart' show computeMixinClass, Emitter;
-import '../model.dart';
-
-import '../../common.dart';
-import '../../closure.dart' show ClosureFieldElement;
-import '../../js/js.dart' as js;
-
-import '../../js_backend/js_backend.dart' show
-    Namer,
-    JavaScriptBackend,
-    JavaScriptConstantCompiler;
-
 import '../js_emitter.dart' show
     ClassStubGenerator,
     CodeEmitterTask,
+    computeMixinClass,
+    Emitter,
     InterceptorStubGenerator,
     MainCallStubGenerator,
     ParameterStubGenerator,
     RuntimeTypeGenerator,
     TypeTestProperties;
+import '../model.dart';
 
+import '../../common.dart';
+import '../../common/names.dart' show
+    Names;
+import '../../compiler.dart' show
+    Compiler;
+import '../../constants/values.dart' show
+    ConstantValue,
+    InterceptorConstantValue;
+import '../../closure.dart' show
+    ClosureFieldElement;
+import '../../dart_types.dart' show
+    DartType;
 import '../../elements/elements.dart' show
+    ClassElement,
+    Element,
+    Elements,
     FieldElement,
+    FunctionElement,
+    FunctionSignature,
+    LibraryElement,
     MethodElement,
-    ParameterElement;
-
-import '../../universe/universe.dart' show Universe, SelectorConstraints;
-import '../../deferred_load.dart' show DeferredLoadTask, OutputUnit;
+    ParameterElement,
+    TypedefElement,
+    VariableElement;
+import '../../js/js.dart' as js;
+import '../../js_backend/js_backend.dart' show
+    Namer,
+    JavaScriptBackend,
+    JavaScriptConstantCompiler;
+import '../../universe/selector.dart' show
+    Selector;
+import '../../universe/universe.dart' show
+    Universe,
+    SelectorConstraints;
+import '../../deferred_load.dart' show
+    DeferredLoadTask,
+    OutputUnit;
 
 part 'collector.dart';
 part 'registry.dart';
 part 'field_visitor.dart';
 
 /// Builds a self-contained representation of the program that can then be
 /// emitted more easily by the individual emitters.
 class ProgramBuilder {
   final Compiler _compiler;
   final Namer namer;
@@ skipping 784 matching lines @@
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     }
   }
 
   Holder _registerStaticStateHolder() {
     return _registry.registerHolder(
         namer.staticStateHolder, isStaticStateHolder: true);
   }
 }