dart2js: patch file support cleanup

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

Index: pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
diff --git a/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart b/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
index dae23f26bc1f5ee8529c9bd236892a4c26367fc1..02e9ffc1bcac47cfdb989b18d80483b36683720a 100644
--- a/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
+++ b/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
@@ -74,10 +74,6 @@ class CodeEmitterTask extends CompilerTask {
 
   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;
 
@@ -215,10 +211,6 @@ class CodeEmitterTask extends CompilerTask {
 }
 
 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;