Heap explorer: Show representation of strings.

Heap explorer: Show representation of strings.

* src/profile-generator.cc (V8HeapExplorer::GetSystemEntryName): For
  maps of strings, return a name that encodes the representation
  strategy used for the strings.
  (V8HeapExplorer::ExtractReferences): For strings, visit the maps as
  well, so that the user can see what representation is used for their
  strings.

See http://wingolog.org/pub/string-representations.png for an example of what it looks like.

BUG=

Committed: https://code.google.com/p/v8/source/detail?r=12973

[Toon Verwaest, 2012-10-30 14:03:33]

lgtm with comment

https://chromiumcodereview.appspot.com/11344021/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/11344021/diff/1/src/profile-generator....
src/profile-generator.cc:1861: SetInternalReference(obj, entry, "map",
obj->map(), HeapObject::kMapOffset);
This seems to be unnecessary given that the same function is called in
if(extract_indexed_refs) below.

[Yang, 2012-10-30 14:39:39]

drive-by comment.

https://chromiumcodereview.appspot.com/11344021/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/11344021/diff/1/src/profile-generator....
src/profile-generator.cc:1980: SetInternalReference(ss, entry, "parent",
ss->parent(), SlicedString::kParentOffset);
Please keep the 80-char limit.

[wingo, 2012-10-31 10:41:13]

On 2012/10/30 14:03:33, Toon Verwaest wrote:
> This seems to be unnecessary given that the same function is called in
> if(extract_indexed_refs) below.

Indeed, fixed.  Fixed the 80-char limit as well.