[base] Revert "Move hashmap allocator to a field"

src/asmjs/asm-typer.cc

Index: src/asmjs/asm-typer.cc
diff --git a/src/asmjs/asm-typer.cc b/src/asmjs/asm-typer.cc
index 7ed54de675fcf2b01f5f7dfcf97de55b5ee1ddc8..20b8d96053d31477ff81d9e9e54a8daa035706e1 100644
--- a/src/asmjs/asm-typer.cc
+++ b/src/asmjs/asm-typer.cc
@@ -361,8 +361,8 @@ bool AsmTyper::AddGlobal(Variable* variable, VariableInfo* info) {
     return false;
   }
 
-  ZoneHashMap::Entry* entry =
-      global_scope_.LookupOrInsert(variable, ComputePointerHash(variable));
+  ZoneHashMap::Entry* entry = global_scope_.LookupOrInsert(
+      variable, ComputePointerHash(variable), ZoneAllocationPolicy(zone_));
 
   if (entry->value != nullptr) {
     return false;
@@ -378,8 +378,8 @@ bool AsmTyper::AddLocal(Variable* variable, VariableInfo* info) {
   DCHECK(!info->IsGlobal());
   DCHECK(ValidAsmIdentifier(variable->name()));
 
-  ZoneHashMap::Entry* entry =
-      local_scope_.LookupOrInsert(variable, ComputePointerHash(variable));
+  ZoneHashMap::Entry* entry = local_scope_.LookupOrInsert(
+      variable, ComputePointerHash(variable), ZoneAllocationPolicy(zone_));
 
   if (entry->value != nullptr) {
     return false;