Make ImmutableArray a sub class of AllStatic.

runtime/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 4914 matching lines @@
   }
 
   RawObject* At(intptr_t index) const {
     return *ObjectAddr(index);
   }
   void SetAt(intptr_t index, const Object& value) const {
     // TODO(iposva): Add storing NoGCScope.
     StorePointer(ObjectAddr(index), value.raw());
   }
 
+  bool IsImmutable() const {
+    return raw()->GetClassId() == kImmutableArrayCid;
+  }
+
   virtual RawAbstractTypeArguments* GetTypeArguments() const {
     return raw_ptr()->type_arguments_;
   }
   virtual void SetTypeArguments(const AbstractTypeArguments& value) const {
     // An Array is raw or takes one type argument. However, its type argument
     // vector may be longer than 1 due to a type optimization reusing the type
     // argument vector of the instantiator.
     ASSERT(value.IsNull() || ((value.Length() >= 1) && value.IsInstantiated()));
     StorePointer(&raw_ptr()->type_arguments_, value.raw());
   }
@@ skipping 53 matching lines @@
     ASSERT((index >= 0) && (index < Length()));
     return &raw_ptr()->data()[index];
   }
 
   void SetLength(intptr_t value) const {
     // This is only safe because we create a new Smi, which does not cause
     // heap allocation.
     raw_ptr()->length_ = Smi::New(value);
   }
 
-  HEAP_OBJECT_IMPLEMENTATION(Array, Instance);
+  FINAL_HEAP_OBJECT_IMPLEMENTATION(Array, Instance);
   friend class Class;
+  friend class ImmutableArray;
   friend class Object;
   friend class String;
 };
 
 
-class ImmutableArray : public Array {
+class ImmutableArray : public AllStatic {
  public:
   static RawImmutableArray* New(intptr_t len, Heap::Space space = Heap::kNew);
 
+  static RawImmutableArray* ReadFrom(SnapshotReader* reader,
+                                     intptr_t object_id,
+                                     intptr_t tags,
+                                     Snapshot::Kind kind);
+
+  static const ClassId kClassId = kImmutableArrayCid;
+
+  static intptr_t InstanceSize() {
+    return Array::InstanceSize();
+  }
+
+  static intptr_t InstanceSize(intptr_t len) {
+    return Array::InstanceSize(len);
+  }
+
  private:
-  FINAL_HEAP_OBJECT_IMPLEMENTATION(ImmutableArray, Array);
+  static RawImmutableArray* raw(const Array& array) {
+    return reinterpret_cast<RawImmutableArray*>(array.raw());
+  }
+
   friend class Class;
 };
 
 
 class GrowableObjectArray : public Instance {
  public:
   intptr_t Capacity() const {
     NoGCScope no_gc;
     ASSERT(!IsNull());
     return Smi::Value(DataArray()->length_);
@@ skipping 836 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_