Add RPC and UI for reachable size of an object / all instances of a class.

runtime/vm/object_graph.h

 // Copyright (c) 2014, 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_GRAPH_H_
 #define VM_OBJECT_GRAPH_H_
 
 #include "vm/allocation.h"
 #include "vm/object.h"
 
@@ skipping 45 matching lines @@
   explicit ObjectGraph(Thread* thread);
   ~ObjectGraph();
 
   // Visits all strongly reachable objects in the isolate's heap, in a
   // pre-order, depth first traversal.
   void IterateObjects(Visitor* visitor);
 
   // Like 'IterateObjects', but restricted to objects reachable from 'root'
   // (including 'root' itself).
   void IterateObjectsFrom(const Object& root, Visitor* visitor);
+  void IterateObjectsFrom(intptr_t class_id, Visitor* visitor);
 
   // The number of bytes retained by 'obj'.
   intptr_t SizeRetainedByInstance(const Object& obj);
+  intptr_t SizeReachableByInstance(const Object& obj);
 
   // The number of bytes retained by the set of all objects of the given class.
   intptr_t SizeRetainedByClass(intptr_t class_id);
+  intptr_t SizeReachableByClass(intptr_t class_id);
 
   // Finds some retaining path from the isolate roots to 'obj'. Populates the
   // provided array with pairs of (object, offset from parent in words),
   // starting with 'obj' itself, as far as there is room. Returns the number
   // of objects on the full path. A null input array behaves like a zero-length
   // input array. The 'offset' of a root is -1.
   //
   // To break the trivial path, the handle 'obj' is temporarily cleared during
   // the search, but restored before returning. If no path is found (i.e., the
   // provided handle was the only way to reach the object), zero is returned.
@@ skipping 12 matching lines @@
   // TODO(koda): Document format; support streaming/chunking.
   intptr_t Serialize(WriteStream* stream);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectGraph);
 };
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_GRAPH_H_