Propagate 'this_object' for method unwind event.

Propagates the 'this_object' to InstrumentationListener::MethodUnwind callback.

Change-Id: I12561f1a611b8399b94e669f9b8a6eaaf1a58631
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index f537709..a2de602 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -136,11 +136,12 @@
     Dbg::PostLocationEvent(method, dex_pc, this_object, Dbg::kMethodExit);
   }
 
-  virtual void MethodUnwind(Thread* thread, const mirror::ArtMethod* method,
-                            uint32_t dex_pc) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  virtual void MethodUnwind(Thread* thread, mirror::Object* this_object,
+                            const mirror::ArtMethod* method, uint32_t dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     // We're not recorded to listen to this kind of event, so complain.
     LOG(ERROR) << "Unexpected method unwind event in debugger " << PrettyMethod(method)
-        << " " << dex_pc;
+               << " " << dex_pc;
   }
 
   virtual void DexPcMoved(Thread* thread, mirror::Object* this_object,