Avoid inlining constants that are used via a deferred import.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to implement [TypedElement.type] because our
  * optimizers may look at its declared type.
@@ skipping 2939 matching lines @@
     if (element != null && element.isForeign(compiler)) {
       visitForeignGetter(send);
     } else if (Elements.isStaticOrTopLevelField(element)) {
       Constant value;
       if (element.isField() && !element.isAssignable()) {
         // A static final or const. Get its constant value and inline it if
         // the value can be compiled eagerly.
         value = backend.constants.getConstantForVariable(element);
       }
       if (value != null) {
-        HConstant instruction = graph.addConstant(value, compiler);
+        HConstant instruction;
+        // Constants that are referred via a deferred prefix should be referred
+        // by reference.
+        PrefixElement prefix = compiler.deferredLoadTask
+            .deferredPrefixElement(send, elements);
+        if (prefix != null) {
+          instruction = graph.addDeferredConstant(value, prefix, compiler);
+        } else {
+          instruction = graph.addConstant(value, compiler);
+        }
         stack.add(instruction);
         // The inferrer may have found a better type than the constant
         // handler in the case of lists, because the constant handler
         // does not look at elements in the list.
         TypeMask type =
             TypeMaskFactory.inferredTypeForElement(element, compiler);
         if (!type.containsAll(compiler) && !instruction.isConstantNull()) {
           // TODO(13429): The inferrer should know that an element
           // cannot be null.
           instruction.instructionType = type.nonNullable();
@@ skipping 3321 matching lines @@
     DartType unaliased = type.unalias(builder.compiler);
     if (unaliased is TypedefType) throw 'unable to unalias $type';
     unaliased.accept(this, builder);
   }
 
   void visitDynamicType(DynamicType type, SsaBuilder builder) {
     ClassElement cls = builder.compiler.findHelper('DynamicRuntimeType');
     builder.push(new HDynamicType(type, new TypeMask.exact(cls)));
   }
 }