Correct capacity reporting for new space; show external size in Observatory.

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"
@@ skipping 55 matching lines @@
 
   // Accessors to generate code for inlined allocation.
   uword* TopAddress() { return &top_; }
   uword* EndAddress() { return &end_; }
   static intptr_t top_offset() { return OFFSET_OF(Scavenger, top_); }
   static intptr_t end_offset() { return OFFSET_OF(Scavenger, end_); }
 
   intptr_t UsedInWords() const {
     return (top_ - FirstObjectStart()) >> kWordSizeLog2;
   }
-  intptr_t CapacityInWords() const { return space_->size() >> kWordSizeLog2; }
+  intptr_t CapacityInWords() const {
+    return (end_ - FirstObjectStart()) >> kWordSizeLog2;
+  }
   intptr_t ExternalInWords() const {
     return external_size_ >> kWordSizeLog2;
   }
 
   void VisitObjects(ObjectVisitor* visitor) const;
   void VisitObjectPointers(ObjectPointerVisitor* visitor) const;
 
   void StartEndAddress(uword* start, uword* end) const {
     *start = to_->start();
     *end = to_->end();
@@ skipping 125 matching lines @@
 
   friend class ScavengerVisitor;
   friend class ScavengerWeakVisitor;
 
   DISALLOW_COPY_AND_ASSIGN(Scavenger);
 };
 
 }  // namespace dart
 
 #endif  // VM_SCAVENGER_H_