Rolling back r10049 due to webkit failures.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 02b4ca11bde91d816f8d6dfcb24bb5dcc9092a86..8aa75804f61942169b49a23d24127748713ef6e7 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -3997,15 +3997,6 @@ Map* Heap::SymbolMapForString(String* string) {
   if (map == external_string_with_ascii_data_map()) {
     return external_symbol_with_ascii_data_map();
   }
-  if (map == short_external_string_map()) {
-    return short_external_symbol_map();
-  }
-  if (map == short_external_ascii_string_map()) {
-    return short_external_ascii_symbol_map();
-  }
-  if (map == short_external_string_with_ascii_data_map()) {
-    return short_external_symbol_with_ascii_data_map();
-  }
 
   // No match found.
   return NULL;