Generalize the interface of page space controller.

runtime/vm/scavenger.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_SCAVENGER_H_
 #define VM_SCAVENGER_H_
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/globals.h"
 #include "vm/raw_object.h"
+#include "vm/spaces.h"
 #include "vm/virtual_memory.h"
 #include "vm/visitor.h"
 
 namespace dart {
 
 // Forward declarations.
 class Heap;
 class Isolate;
 class JSONObject;
 class ScavengerVisitor;
@@ skipping 51 matching lines @@
 
   intptr_t UsedInWords() const {
     return (top_ - FirstObjectStart()) >> kWordSizeLog2;
   }
   intptr_t CapacityInWords() const {
     return (end_ - FirstObjectStart()) >> kWordSizeLog2;
   }
   intptr_t ExternalInWords() const {
     return external_size_ >> kWordSizeLog2;
   }
+  SpaceUsage GetCurrentUsage() const {
+    SpaceUsage usage;
+    usage.used_in_words = UsedInWords();
+    usage.capacity_in_words = CapacityInWords();
+    usage.external_in_words = ExternalInWords();
+    return usage;
+  }
 
   void VisitObjects(ObjectVisitor* visitor) const;
   void VisitObjectPointers(ObjectPointerVisitor* visitor) const;
 
   void StartEndAddress(uword* start, uword* end) const {
     *start = to_->start();
     *end = to_->end();
   }
 
   // Returns true if the last scavenge had a promotion failure.
@@ skipping 118 matching lines @@
 
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // VM_SCAVENGER_H_