Fix some Mac OS size_t versus int complaints.

Change-Id: I80bd0737122e76b42090fa0eed9b3f7c33b3640b
diff --git a/src/check_jni.cc b/src/check_jni.cc
index 89f0693..4b17ad8 100644
--- a/src/check_jni.cc
+++ b/src/check_jni.cc
@@ -894,7 +894,7 @@
   const char* function_name_;
   int flags_;
   bool has_method_;
-  size_t indent_;
+  int indent_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedCheck);
 };