Rename Constant to ConstantValue and ConstExp to ConstantExpression.

sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart
index 562201aad64115afec715228e85d7fc83bdadcb4..e979a2b245e75368b42c61aa46948e86027456c2 100644
--- a/sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart_backend/backend.dart
@@ -410,19 +410,19 @@ class DartConstantTask extends ConstantCompilerTask
 
   String get name => 'ConstantHandler';
 
-  ConstExp getConstantForVariable(VariableElement element) {
+  ConstantExpression getConstantForVariable(VariableElement element) {
     return constantCompiler.getConstantForVariable(element);
   }
 
-  ConstExp getConstantForNode(Node node, TreeElements elements) {
+  ConstantExpression getConstantForNode(Node node, TreeElements elements) {
     return constantCompiler.getConstantForNode(node, elements);
   }
 
-  ConstExp getConstantForMetadata(MetadataAnnotation metadata) {
+  ConstantExpression getConstantForMetadata(MetadataAnnotation metadata) {
     return metadata.constant;
   }
 
-  ConstExp compileConstant(VariableElement element) {
+  ConstantExpression compileConstant(VariableElement element) {
     return measure(() {
       return constantCompiler.compileConstant(element);
     });
@@ -434,13 +434,13 @@ class DartConstantTask extends ConstantCompilerTask
     });
   }
 
-  ConstExp compileNode(Node node, TreeElements elements) {
+  ConstantExpression compileNode(Node node, TreeElements elements) {
     return measure(() {
       return constantCompiler.compileNodeWithDefinitions(node, elements);
     });
   }
 
-  ConstExp compileMetadata(MetadataAnnotation metadata,
+  ConstantExpression compileMetadata(MetadataAnnotation metadata,
                            Node node,
                            TreeElements elements) {
     return measure(() {