dart2js: patch file support cleanup

pkg/compiler/lib/src/js_emitter/code_emitter_task.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.js_emitter.code_emitter_task;
 
 import 'package:js_runtime/shared/embedded_names.dart' show JsBuiltin;
 
 import '../common.dart';
 import '../common/tasks.dart' show CompilerTask;
@@ skipping 56 matching lines @@
   }
 
   Emitter get emitter {
     assert(invariant(NO_LOCATION_SPANNABLE, _emitter != null,
         message: "Emitter has not been created yet."));
     return _emitter;
   }
 
   String get name => 'Code emitter';
 
-  /// Returns the string that is used to find library patches that are
-  /// specialized for the emitter.
-  String get patchVersion => _emitterFactory.patchVersion;
-
   /// Returns true, if the emitter supports reflection.
   bool get supportsReflection => _emitterFactory.supportsReflection;
 
   /// Returns the closure expression of a static function.
   jsAst.Expression isolateStaticClosureAccess(FunctionEntity element) {
     return emitter.isolateStaticClosureAccess(element);
   }
 
   /// Returns the JS function that must be invoked to get the value of the
   /// lazily initialized static.
@@ skipping 117 matching lines @@
           isMockCompilation: compiler.isMockCompilation);
       int size = emitter.emitProgram(programBuilder);
       // TODO(floitsch): we shouldn't need the `neededClasses` anymore.
       neededClasses = programBuilder.collector.neededClasses;
       return size;
     });
   }
 }
 
 abstract class EmitterFactory {
-  /// Returns the string that is used to find library patches that are
-  /// specialized for this emitter.
-  String get patchVersion;
-
   /// Returns true, if the emitter supports reflection.
   bool get supportsReflection;
 
   /// Create the [Emitter] for the emitter [task] that uses the given [namer].
   Emitter createEmitter(
       CodeEmitterTask task, Namer namer, ClosedWorld closedWorld);
 }
 
 abstract class Emitter {
   /// Uses the [programBuilder] to generate a model of the program, emits
@@ skipping 39 matching lines @@
 
   /// Returns the JS code for accessing the given [constant].
   jsAst.Expression constantReference(ConstantValue constant);
 
   /// Returns the JS template for the given [builtin].
   jsAst.Template templateForBuiltin(JsBuiltin builtin);
 
   /// Returns the size of the code generated for a given output [unit].
   int generatedSize(OutputUnit unit);
 }