Use GrowableObjectArray in the debugger instance/static field lists.

Use GrowableObjectArray in the debugger instance/static field lists.
Committed: https://code.google.com/p/dart/source/detail?r=5148

[hausner, 2012-03-08 01:06:56]

LGTM

The function ActivationFrame::GetDescIndices() could maybe also use a growable
array and return the variable names and values directly rather than an array of
descriptor indices. Please add a TODO(hausner) there to remind me to take a
closer look.

[siva, 2012-03-08 01:24:15]

Thanks.

Added the TODO.