Wrap Import uses in deferred_load.dart

pkg/compiler/lib/src/ssa/builder.dart

Index: pkg/compiler/lib/src/ssa/builder.dart
diff --git a/pkg/compiler/lib/src/ssa/builder.dart b/pkg/compiler/lib/src/ssa/builder.dart
index 209e15108f662e6a44d5eadf6eddf54474b3c4f7..7239a44dd6c80d2d8cb97cf548457bd19f7440cc 100644
--- a/pkg/compiler/lib/src/ssa/builder.dart
+++ b/pkg/compiler/lib/src/ssa/builder.dart
@@ -3338,7 +3338,7 @@ class SsaBuilder extends ast.Visitor
                                              ast.Node location) {
     if (prefixElement == null) return;
     String loadId =
-        compiler.deferredLoadTask.importDeferName[prefixElement.deferredImport];
+        compiler.deferredLoadTask.getImportDeferName(location, prefixElement);
     HInstruction loadIdConstant = addConstantString(loadId);
     String uri = prefixElement.deferredImport.uri.dartString.slowToString();
     HInstruction uriConstant = addConstantString(uri);
@@ -4413,8 +4413,8 @@ class SsaBuilder extends ast.Visitor
     invariant(node, deferredLoader.isDeferredLoaderGetter);
     Element loadFunction = compiler.loadLibraryFunction;
     PrefixElement prefixElement = deferredLoader.enclosingElement;
-    String loadId = compiler.deferredLoadTask
-        .importDeferName[prefixElement.deferredImport];
+    String loadId =
+        compiler.deferredLoadTask.getImportDeferName(node, prefixElement);
     var inputs = [graph.addConstantString(
         new ast.DartString.literal(loadId), compiler)];
     push(new HInvokeStatic(loadFunction, inputs, backend.nonNullType,