Make isEmpty a getter.

lib/compiler/implementation/ssa/codegen.dart

Index: lib/compiler/implementation/ssa/codegen.dart
diff --git a/lib/compiler/implementation/ssa/codegen.dart b/lib/compiler/implementation/ssa/codegen.dart
index d8cda34819f032deac654b695f644fdd9f52c831..09f624da902f16300122bbe88e5b5f642baab321 100644
--- a/lib/compiler/implementation/ssa/codegen.dart
+++ b/lib/compiler/implementation/ssa/codegen.dart
@@ -319,7 +319,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
    * to the [statement].
    */
   void pushStatement(js.Statement statement, [HInstruction instruction]) {
-    assert(expressionStack.isEmpty());
+    assert(expressionStack.isEmpty);
     if (instruction != null) {
       attachLocation(statement, instruction);
     }
@@ -405,7 +405,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     subGraph = new SubGraph(graph.entry, graph.exit);
     HBasicBlock start = beginGraph(graph);
     visitBasicBlock(start);
-    if (!delayedVariableDeclarations.isEmpty()) {
+    if (!delayedVariableDeclarations.isEmpty) {
       List<js.VariableInitialization> declarations =
           <js.VariableInitialization>[];
       delayedVariableDeclarations.forEach((String name) {
@@ -460,8 +460,8 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
         // HFieldSet generates code on the form x.y = ..., which isn't
         // valid in a declaration, but it also always have no uses, so
         // it's caught by that test too.
-        assert(current is! HFieldSet || current.usedBy.isEmpty());
-        if (current.usedBy.isEmpty()) {
+        assert(current is! HFieldSet || current.usedBy.isEmpty);
+        if (current.usedBy.isEmpty) {
           result = TYPE_EXPRESSION;
         }
         current = current.next;
@@ -559,7 +559,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     visitSubGraph(expressionSubGraph.subExpression);
     expressionStack = oldExpressionStack;
     isGeneratingExpression = oldIsGeneratingExpression;
-    if (sequenceElements.isEmpty()) {
+    if (sequenceElements.isEmpty) {
       // Happens when the initializer, condition or update of a loop is empty.
       return null;
     } else if (sequenceElements.length == 1) {
@@ -687,7 +687,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
   visitStatement(HInstruction node) {
     assert(!isGeneratingExpression);
     visit(node);
-    if (!expressionStack.isEmpty()) {
+    if (!expressionStack.isEmpty) {
       assert(expressionStack.length == 1);
       pushExpressionAsStatement(pop());
     }
@@ -1005,7 +1005,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     endLabeledBlock(labeledBlockInfo);
 
     if (labeledBlockInfo.isContinue) {
-      while (!continueOverrides.isEmpty()) {
+      while (!continueOverrides.isEmpty) {
         continueAction.remove(continueOverrides.head);
         continueOverrides = continueOverrides.tail;
       }
@@ -1146,8 +1146,8 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
       }
     }
 
-    while (!worklist.isEmpty()) {
-      while (!ready.isEmpty()) {
+    while (!worklist.isEmpty) {
+      while (!ready.isEmpty) {
         String destination = ready.removeLast();
         String source = initialValue[destination];
         // Since [source] might have been updated, use the current
@@ -1323,7 +1323,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     // one dominated block (since it has only one successor).
     // If the successor is dominated by another block, then the other block
     // is responsible for visiting the successor.
-    if (dominated.isEmpty()) return;
+    if (dominated.isEmpty) return;
     if (dominated.length > 2) {
       compiler.internalError('dominated.length = ${dominated.length}',
                              instruction: node);
@@ -1675,7 +1675,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     String code = node.code.slowToString();
     List<HInstruction> inputs = node.inputs;
     if (node.isJsStatement(types)) {
-      if (!inputs.isEmpty()) {
+      if (!inputs.isEmpty) {
         compiler.internalError("foreign statement with inputs: $code",
                                instruction: node);
       }