Rename GlobalSynchronization to Locks

Also address some review comments in common_throws relating to
ToStr<InvokeType> and exception detail messages.

Change-Id: Ibf2c0f147689fa236d349bd7f01eed3c2522552b
diff --git a/test/StackWalk/stack_walk_jni.cc b/test/StackWalk/stack_walk_jni.cc
index 41e8d58..444eaed 100644
--- a/test/StackWalk/stack_walk_jni.cc
+++ b/test/StackWalk/stack_walk_jni.cc
@@ -42,11 +42,11 @@
 struct TestReferenceMapVisitor : public StackVisitor {
   explicit TestReferenceMapVisitor(const ManagedStack* stack,
                                    const std::vector<TraceStackFrame>* trace_stack)
-      SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
       : StackVisitor(stack, trace_stack, NULL) {
   }
 
-  bool VisitFrame() SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
+  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     Method* m = GetMethod();
     CHECK(m != NULL);
     LOG(INFO) << "At " << PrettyMethod(m, false);