Avoid inlining constants that are used via a deferred import.

sdk/lib/_internal/compiler/implementation/deferred_load.dart

 // Copyright (c) 2014, 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.
 
 library deferred_load;
 
 import 'dart2jslib.dart' show
     Backend,
     Compiler,
     CompilerTask,
     Constant,
     ConstructedConstant,
     MessageKind,
+    DeferredConstant,
     StringConstant,
-    invariant,
-    Backend;
+    invariant;
 
 import 'dart_backend/dart_backend.dart' show
     DartBackend;
 
 import 'js_backend/js_backend.dart' show
     JavaScriptBackend;
 
 import 'elements/elements.dart' show
     Element,
     ClassElement,
@@ skipping 157 matching lines @@
 
   bool isDeferred(Element element) {
     return outputUnitForElement(element) != mainOutputUnit;
   }
 
   /// Returns true if e1 and e2 are in the same output unit.
   bool inSameOutputUnit(Element e1, Element e2) {
     return outputUnitForElement(e1) == outputUnitForElement(e2);
   }
 
+  void registerConstantDeferredUse(DeferredConstant constant,
+                                   PrefixElement prefix) {
+    OutputUnit outputUnit = new OutputUnit();
+    outputUnit.imports.add(prefix.deferredImport);
+    _constantToOutputUnit[constant] = outputUnit;
+  }
+
   /// Mark that [import] is part of the [OutputputUnit] for [element].
   ///
   /// [element] can be either a [Constant] or an [Element].
   void _addImportToOutputUnitOfElement(Element element, Import import) {
     // Only one file should be loaded when the program starts, so make
     // sure that only one OutputUnit is created for [fakeMainImport].
     if (import == _fakeMainImport) {
       _elementToOutputUnit[element] = mainOutputUnit;
     }
     _elementToOutputUnit.putIfAbsent(element, () => new OutputUnit())
@@ skipping 673 matching lines @@
     Element maybePrefix = elements[identifier];
     if (maybePrefix != null && maybePrefix.isPrefix()) {
       PrefixElement prefixElement = maybePrefix;
       if (prefixElement.isDeferred) {
         return prefixElement;
       }
     }
     return null;
   }
 }