Hide collection-dev library.

compiler/java/com/google/dart/compiler/SystemLibraryManager.java

Index: compiler/java/com/google/dart/compiler/SystemLibraryManager.java
diff --git a/compiler/java/com/google/dart/compiler/SystemLibraryManager.java b/compiler/java/com/google/dart/compiler/SystemLibraryManager.java
index 63626bccb48cd3dc1b689333b4ab73c9bbe2b7d4..a86558ef4660cde66090403652308023eee14adc 100644
--- a/compiler/java/com/google/dart/compiler/SystemLibraryManager.java
+++ b/compiler/java/com/google/dart/compiler/SystemLibraryManager.java
@@ -138,7 +138,10 @@ public class SystemLibraryManager  {
     HashSet<String> explicitShortNames = new HashSet<String>();
     
     for (Entry<String, DartLibrary> entry : declaredLibraries.entrySet()) {
-      if (entry.getValue().getCategory().equals("Internal")){
+      if (entry.getValue().getCategory().equals("Internal")
+          // TODO(8365): the following line allows dart:_collection-dev to
+          // be imported even though it's a hidden library.
+          && !entry.getKey().equals("dart:_collection-dev")) {
         continue;
       }
       String shortName = entry.getKey().trim();