StringTable::Lookup*IfExist() handlified.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include "allocation.h"
 #include "assert-scope.h"
 #include "builtins.h"
@@ skipping 3813 matching lines @@
   static const int kPrefixSize = 0;
   static const int kEntrySize = 1;
 };
 
 class SeqOneByteString;
 
 // StringTable.
 //
 // No special elements in the prefix and the element size is 1
 // because only the string itself (the key) needs to be stored.
-// TODO(ishell): Make StringTable a singleton class and move
-//   Heap::InternalizeStringXX() methods here.
 class StringTable: public HashTable<StringTable,
                                     StringTableShape,
                                     HashTableKey*> {
  public:
   // Find string in the string table. If it is not there yet, it is
   // added. The return value is the string found.
   static Handle<String> LookupString(Isolate* isolate, Handle<String> key);
   static Handle<String> LookupKey(Isolate* isolate, HashTableKey* key);
 
+  // Tries to internalize given string and returns string handle on success
+  // or an empty handle otherwise.
+  MUST_USE_RESULT static MaybeHandle<String> InternalizeStringIfExists(
+      Isolate* isolate,
+      Handle<String> string);
+
   // Looks up a string that is equal to the given string and returns
-  // true if it is found, assigning the string to the given output
-  // parameter.
-  bool LookupStringIfExists(String* str, String** result);
-  bool LookupTwoCharsStringIfExists(uint16_t c1, uint16_t c2, String** result);
+  // string handle if it is found, or an empty handle otherwise.
+  MUST_USE_RESULT static MaybeHandle<String> LookupStringIfExists(
+      Isolate* isolate,
+      Handle<String> str);
+  MUST_USE_RESULT static MaybeHandle<String> LookupTwoCharsStringIfExists(
+      Isolate* isolate,
+      uint16_t c1,
+      uint16_t c2);
 
   // Casting.
   static inline StringTable* cast(Object* obj);
 
  private:
   template <bool seq_ascii> friend class JsonParser;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StringTable);
 };
 
@@ skipping 7311 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_