Use UndoDebuggerSuspensions for JDWP ResumeVM rather than weakening ResumeAll's checking.

Change-Id: I3ba71fb9e84664f130dd29ba8c13a8e1b6c18e46
diff --git a/src/thread_list.cc b/src/thread_list.cc
index 951a2be..186ddbc 100644
--- a/src/thread_list.cc
+++ b/src/thread_list.cc
@@ -274,7 +274,7 @@
     MutexLock mu(thread_suspend_count_lock_);
     for (It it = list_.begin(), end = list_.end(); it != end; ++it) {
       Thread* thread = *it;
-      if (thread == self || (for_debugger && thread == debug_thread) || thread->suspend_count_ == 0) {
+      if (thread == self || (for_debugger && thread == debug_thread)) {
         continue;
       }
       ModifySuspendCount(thread, -1, for_debugger);