Move registering of interceptors to the JsBackend.

lib/compiler/implementation/compiler.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.
 
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
 const bool REPORT_EXCESS_RESOLUTION = false;
@@ skipping 52 matching lines @@
   Backend(this.compiler,
           [ConstantSystem constantSystem = DART_CONSTANT_SYSTEM])
       : this.constantSystem = constantSystem;
 
   void enqueueAllTopLevelFunctions(LibraryElement lib, Enqueuer world) {
     lib.forEachExport((Element e) {
       if (e.isFunction()) world.addToWorkList(e);
     });
   }
 
+  abstract void onUseSelector(Selector selector, Enqueuer world);
   abstract void enqueueHelpers(Enqueuer world);
   abstract void codegen(WorkItem work);
   abstract void processNativeClasses(Enqueuer world,
                                      Collection<LibraryElement> libraries);
   abstract void assembleProgram();
   abstract List<CompilerTask> get tasks;
 
   ItemCompilationContext createItemCompilationContext() {
     return new ItemCompilationContext();
   }
@@ skipping 861 matching lines @@
     final endOffset = end.charOffset + end.slowCharCount;
 
     // [begin] and [end] might be the same for the same empty token. This
     // happens for instance when scanning '$$'.
     assert(endOffset >= beginOffset);
     return f(beginOffset, endOffset);
   }
 
   String toString() => 'SourceSpan($uri, $begin, $end)';
 }