Allow externalization of canonical strings also. Only restrict canonical strings

vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 4037 matching lines @@
 
   static RawString* Transform(int32_t (*mapping)(int32_t ch),
                               const String& str,
                               Heap::Space space = Heap::kNew);
 
   static RawString* ToUpperCase(const String& str,
                                 Heap::Space space = Heap::kNew);
   static RawString* ToLowerCase(const String& str,
                                 Heap::Space space = Heap::kNew);
 
+  static bool EqualsIgnoringPrivateKey(const String& str1,
+                                       const String& str2);
+
   static RawString* NewFormatted(const char* format, ...)
       PRINTF_ATTRIBUTE(1, 2);
   static RawString* NewFormattedV(const char* format, va_list args);
 
  protected:
   bool HasHash() const {
     ASSERT(Smi::New(0) == NULL);
     return (raw_ptr()->hash_ != NULL);
   }
 
@@ skipping 30 matching lines @@
 
 class OneByteString : public AllStatic {
  public:
   static int32_t CharAt(const String& str, intptr_t index) {
     return *CharAddr(str, index);
   }
 
   static RawOneByteString* EscapeSpecialCharacters(const String& str,
                                                    bool raw_str);
 
-  static bool EqualsIgnoringPrivateKey(const String& str1,
-                                       const String& str2);
-
   // We use the same maximum elements for all strings.
   static const intptr_t kBytesPerElement = 1;
   static const intptr_t kMaxElements = String::kMaxElements;
 
   static intptr_t data_offset() { return OFFSET_OF(RawOneByteString, data_); }
 
   static intptr_t InstanceSize() {
     ASSERT(sizeof(RawOneByteString) == OFFSET_OF(RawOneByteString, data_));
     return 0;
   }
@@ skipping 2131 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_