dart2js cps: Use 'this' instead of receiver when possible.

pkg/compiler/lib/src/js_backend/codegen/glue.dart

Index: pkg/compiler/lib/src/js_backend/codegen/glue.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/glue.dart b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
index a68f06801740ca011c28db2f566aa54d8e444983..2029c09bcd0fe0116f20d9dfb8fe337fffdbfe2b 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/glue.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
@@ -54,6 +54,10 @@ class Glue {
     _compiler.internalError(_compiler.currentElement, message);
   }
 
+  bool isUsedAsMixin(ClassElement clazz) {

[sra1, 2015/08/26 15:04:43]

nit: I'm not a fan of the non-word 'clazz'.
Other places in the compiler use 'element' or 'classElement'.
I'd prefer the CPS files were consistent.

+    return classWorld.isUsedAsMixin(clazz);
+  }
+
   ConstantValue getConstantValueForVariable(VariableElement variable) {
     return _backend.constants.getConstantValueForVariable(variable);
   }
@@ -114,6 +118,10 @@ class Glue {
     return _backend.isInterceptedMethod(element);
   }
 
+  bool isInterceptorClass(ClassElement element) {
+    return element.isSubclassOf(_backend.jsInterceptorClass);
+  }
+
   Set<ClassElement> getInterceptedClassesOn(Selector selector) {
     return _backend.getInterceptedClassesOn(selector.name);
   }