Convert to new enter method

ppapi/thunk/ppb_mouse_lock_thunk.cc

Index: ppapi/thunk/ppb_mouse_lock_thunk.cc
diff --git a/ppapi/thunk/ppb_mouse_lock_thunk.cc b/ppapi/thunk/ppb_mouse_lock_thunk.cc
index 167a53748b238f11487f446f4a8f6f3ef83a9977..11d2012805498c198dba9b04fe0c23fb328c5dbd 100644
--- a/ppapi/thunk/ppb_mouse_lock_thunk.cc
+++ b/ppapi/thunk/ppb_mouse_lock_thunk.cc
@@ -4,7 +4,6 @@
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_mouse_lock.h"
-#include "ppapi/thunk/common.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 #include "ppapi/thunk/thunk.h"
@@ -15,11 +14,10 @@ namespace thunk {
 namespace {
 
 int32_t LockMouse(PP_Instance instance, PP_CompletionCallback callback) {
-  EnterFunction<PPB_Instance_FunctionAPI> enter(instance, true);
+  EnterFunction<PPB_Instance_FunctionAPI> enter(instance, callback, true);
   if (enter.failed())
-    return MayForceCallback(callback, PP_ERROR_BADARGUMENT);
-  int32_t result = enter.functions()->LockMouse(instance, callback);
-  return MayForceCallback(callback, result);
+    return enter.retval();
+  return enter.SetResult(enter.functions()->LockMouse(instance, callback));
 }
 
 void UnlockMouse(PP_Instance instance) {