Preload DexCaches

Bug: 11045348
Change-Id: I6f9c0d11613b6b4933a04ae23dbf4bc7879cea65
diff --git a/runtime/dex_file.h b/runtime/dex_file.h
index 346154c..cef4ce4 100644
--- a/runtime/dex_file.h
+++ b/runtime/dex_file.h
@@ -33,6 +33,8 @@
 
 namespace art {
 
+// TODO: remove dependencies on mirror classes, primarily by moving
+// EncodedStaticFieldValueIterator to its own file.
 namespace mirror {
   class ArtField;
   class ArtMethod;