Revert "Support runtime check of function types."

sdk/lib/_internal/compiler/implementation/js_backend/namer.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/namer.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/namer.dart b/sdk/lib/_internal/compiler/implementation/js_backend/namer.dart
index a15f5e00f55fe0af25c2619b144876434bec1982..77766ebfbce3698350bc231bdfbc27ed5dcd9ddf 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/namer.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/namer.dart
@@ -173,7 +173,6 @@ class Namer implements ClosureNamer {
   }
 
   final String CURRENT_ISOLATE;
-  String get GLOBAL_OBJECT => CURRENT_ISOLATE;
 
   final String getterPrefix = r'get$';
   final String setterPrefix = r'set$';
@@ -767,41 +766,6 @@ class Namer implements ClosureNamer {
 
   String operatorAsPrefix() => r'$as';
 
-  String operatorSignature() => r'$signature';
-
-  String functionTypeTag() => r'func';
-
-  String functionTypeVoidReturnTag() => r'void';
-
-  String functionTypeReturnTypeTag() => r'ret';
-
-  String functionTypeRequiredParametersTag() => r'args';
-
-  String functionTypeOptionalParametersTag() => r'opt';
-
-  String functionTypeNamedParametersTag() => r'named';
-
-  Map<FunctionType,String> functionTypeNameMap =
-      new Map<FunctionType,String>();
-  FunctionTypeNamer functionTypeNamer = new FunctionTypeNamer();
-
-  String getFunctionTypeName(FunctionType functionType) {
-    return functionTypeNameMap.putIfAbsent(functionType, () {
-      String proposedName = functionTypeNamer.computeName(functionType);
-      String freshName = getFreshName(proposedName, usedInstanceNames,
-                                      suggestedInstanceNames, ensureSafe: true);
-      return freshName;
-    });
-  }
-
-  String operatorIsType(DartType type) {
-    if (type.kind == TypeKind.FUNCTION) {
-      // TODO(erikcorry): Reduce from $isx to ix when we are minifying.
-      return '${operatorIsPrefix()}_${getFunctionTypeName(type)}';
-    }
-    return operatorIs(type.element);
-  }
-
   String operatorIs(Element element) {
     // TODO(erikcorry): Reduce from $isx to ix when we are minifying.
     return '${operatorIsPrefix()}${getRuntimeTypeName(element)}';
@@ -823,20 +787,6 @@ class Namer implements ClosureNamer {
     return '${operatorAsPrefix()}${getName(element)}';
   }
 
-  String signatureLocation(FunctionType type) {
-    ClassElement classElement = Types.getClassContext(type);
-    if (classElement != null) {
-      return '${isolateAccess(classElement)}';
-    } else {
-      return '${GLOBAL_OBJECT}';
-    }
-  }
-
-  String signatureName(FunctionType type) {
-    String signature = '${operatorSignature()}_${getFunctionTypeName(type)}';
-    return '${signatureLocation(type)}.$signature';
-  }
-
   String safeName(String name) => _safeName(name, jsReserved);
   String safeVariableName(String name) => _safeName(name, jsVariableReserved);
 
@@ -891,6 +841,7 @@ class Namer implements ClosureNamer {
   }
 }
 
+
 /**
  * Generator of names for [Constant] values.
  *
@@ -1064,6 +1015,7 @@ class ConstantNamingVisitor implements ConstantVisitor {
   }
 }
 
+
 /**
  * Generates canonical hash values for [Constant]s.
  *
@@ -1209,56 +1161,3 @@ class ConstantCanonicalHasher implements ConstantVisitor<int> {
     return _MASK & (hash + (((_MASK >> 15) & hash) << 15));
   }
 }
-
-class FunctionTypeNamer extends DartTypeVisitor {
-  StringBuffer sb;
-
-  String computeName(DartType type) {
-    sb = new StringBuffer();
-    visit(type);
-    return sb.toString();
-  }
-
-  visit(DartType type) {
-    type.accept(this, null);
-  }
-
-  visitType(DartType type, _) {
-    sb.write(type.name.slowToString());
-  }
-
-  visitFunctionType(FunctionType type, _) {
-    visit(type.returnType);
-    sb.write('_');
-    for (Link<DartType> link = type.parameterTypes;
-         !link.isEmpty;
-         link = link.tail) {
-      sb.write('_');
-      visit(link.head);
-    }
-    bool first = false;
-    for (Link<DartType> link = type.optionalParameterTypes;
-         !link.isEmpty;
-         link = link.tail) {
-      if (!first) {
-        sb.write('_');
-      }
-      sb.write('_');
-      visit(link.head);
-      first = true;
-    }
-    if (!type.namedParameterTypes.isEmpty) {
-      first = false;
-      for (Link<DartType> link = type.namedParameterTypes;
-          !link.isEmpty;
-          link = link.tail) {
-        if (!first) {
-          sb.write('_');
-        }
-        sb.write('_');
-        visit(link.head);
-        first = true;
-      }
-    }
-  }
-}