Added {Zone}GrowableHandlePtrArray types: simplifies code, makes code safer

runtime/vm/symbols.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/symbols.h"
 
 #include "vm/handles.h"
 #include "vm/handles_impl.h"
 #include "vm/hash_table.h"
 #include "vm/isolate.h"
@@ skipping 377 matching lines @@
   } else if (str2.Length() == 0) {
     return New(str1);
   } else {
     return NewSymbol(ConcatString(str1, str2));
   }
 }
 
 
 // TODO(srdjan): If this becomes performance critical code, consider looking
 // up symbol from pieces instead of concatenating them first into a big string.
-RawString* Symbols::FromConcatAll(const GrowableArray<const String*>& strs) {
+RawString* Symbols::FromConcatAll(
+    const GrowableHandlePtrArray<const String>& strs) {
   GrowableArray<const char*> cchars(strs.length());
   GrowableArray<intptr_t> lengths(strs.length());
   intptr_t len_sum = 0;
   for (intptr_t i = 0; i < strs.length(); i++) {
-    const char* to_cstr = strs[i]->ToCString();
+    const char* to_cstr = strs[i].ToCString();
     intptr_t len = strlen(to_cstr);
     cchars.Add(to_cstr);
     lengths.Add(len);
     len_sum += len;
   }
 
   Zone* zone = Thread::Current()->zone();
   char* buffer = zone->Alloc<char>(len_sum);
   const char* const orig_buffer = buffer;
   for (intptr_t i = 0; i < cchars.length(); i++) {
@@ skipping 82 matching lines @@
 RawObject* Symbols::GetVMSymbol(intptr_t object_id) {
   ASSERT(IsVMSymbolId(object_id));
   intptr_t i = (object_id - kMaxPredefinedObjectIds);
   if ((i > kIllegal) && (i < Symbols::kMaxPredefinedId)) {
     return symbol_handles_[i]->raw();
   }
   return Object::null();
 }
 
 }  // namespace dart