Basic GC logging (and class initialization timing).

Change-Id: Ibb09e556fbd42b1bb8cbd72974e8ca226aa073a5
diff --git a/src/utils.h b/src/utils.h
index 4f58c52..228925d 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -198,6 +198,9 @@
 // Returns the current date in ISO yyyy-mm-dd hh:mm:ss format.
 std::string GetIsoDate();
 
+// Returns the current time in nanoseconds (using the POSIX CLOCK_MONOTONIC).
+uint64_t NanoTime();
+
 // Splits a string using the given delimiter character into a vector of
 // strings. Empty strings will be omitted.
 void Split(const std::string& s, char delim, std::vector<std::string>& result);