This is reapplying r9501 with this single change which seemed to be causing most (all) of the failures for r9501.

--- a/src/debug.cc
+++ b/src/debug.cc
@@ -2230,6 +2230,7 @@ Debugger::Debugger(Isolate* isolate)
       compiling_natives_(false),
       is_loading_debugger_(false),
       never_unload_debugger_(false),
+      force_debugger_active_(true),
       message_handler_(NULL),
       debugger_unload_pending_(false),
       host_dispatch_handler_(NULL),

R=kmillikin@chromium.org

BUG=
TEST=

Review URL: http://codereview.chromium.org//8337009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9684 ce2b1a6d-e550-0410-aec6-3dcde31c8c00