- Use a map to lookup libraries by URL.

runtime/vm/raw_object_snapshot.cc

Index: runtime/vm/raw_object_snapshot.cc
diff --git a/runtime/vm/raw_object_snapshot.cc b/runtime/vm/raw_object_snapshot.cc
index eec25231efd802fd6b598fb917a80a67a9f7dd3f..14169bae7ab1520f0399c9e89cf0e6a3fc7ba025 100644
--- a/runtime/vm/raw_object_snapshot.cc
+++ b/runtime/vm/raw_object_snapshot.cc
@@ -1132,7 +1132,7 @@ RawLibrary* Library::ReadFrom(SnapshotReader* reader,
   if ((kind == Snapshot::kScript) && is_in_fullsnapshot) {
     // Lookup the object as it should already exist in the heap.
     *reader->StringHandle() ^= reader->ReadObjectImpl(kAsInlinedObject);
-    library = Library::LookupLibrary(*reader->StringHandle());
+    library = Library::LookupLibrary(reader->thread(), *reader->StringHandle());
     ASSERT(library.is_in_fullsnapshot());
   } else {
     // Allocate library object.
@@ -1174,7 +1174,7 @@ RawLibrary* Library::ReadFrom(SnapshotReader* reader,
     if (!Snapshot::IsFull(kind)) {
       // The cache of resolved names in library scope is not serialized.
       library.InitResolvedNamesCache(kInitialNameCacheSize);
-      library.Register();
+      library.Register(reader->thread());
     } else {
       library.InitResolvedNamesCache(kInitialNameCacheSize, reader);
     }