Revert "Rename internal library dart:_collection-dev to dart:_internal."

sdk/lib/_internal/compiler/implementation/js_backend/backend.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 js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 1551 matching lines @@
       symbolsUsed.add(name.substring(0, name.length - 1));
     }
   }
 
   /// Called when [:new Symbol(...):] is seen.
   void registerNewSymbol(TreeElements elements) {
   }
 
   /// Called when resolving the `Symbol` constructor.
   void registerSymbolConstructor(TreeElements elements) {
-    // Make sure that collection_dev.Symbol.validated is registered.
+    // Make sure that _internals.Symbol.validated is registered.
     assert(compiler.symbolValidatedConstructor != null);
     enqueueInResolution(compiler.symbolValidatedConstructor, elements);
   }
 
   /// Should [element] (a getter) be retained for reflection?
   bool shouldRetainGetter(Element element) => isNeededForReflection(element);
 
   /// Should [element] (a setter) be retained for reflection?
   bool shouldRetainSetter(Element element) => isNeededForReflection(element);
 
@@ skipping 290 matching lines @@
     copy(constant.values);
     copy(constant.protoValue);
     copy(constant);
   }
 
   void visitConstructed(ConstructedConstant constant) {
     copy(constant.fields);
     copy(constant);
   }
 }