Add root types and thread id to root visiting.

Enables us to pass the root type and thread id to hprof.

Bug: 12680863
Change-Id: I6a0f1f9e3aa8f9b4033d695818ae7ca3460d67cb
diff --git a/runtime/mirror/throwable.cc b/runtime/mirror/throwable.cc
index 2318b74..a57bd43 100644
--- a/runtime/mirror/throwable.cc
+++ b/runtime/mirror/throwable.cc
@@ -93,9 +93,10 @@
   java_lang_Throwable_ = NULL;
 }
 
-void Throwable::VisitRoots(RootVisitor* visitor, void* arg) {
+void Throwable::VisitRoots(RootCallback* callback, void* arg) {
   if (java_lang_Throwable_ != nullptr) {
-    java_lang_Throwable_ = down_cast<Class*>(visitor(java_lang_Throwable_, arg));
+    java_lang_Throwable_ = down_cast<Class*>(callback(java_lang_Throwable_, arg, 0,
+                                                      kRootStickyClass));
   }
 }