Bug 920909 - Fix lossy startTime fields serialization. r=ehsan

tools/profiler/JSCustomObjectBuilder.cpp

@@ -154,6 +154,16 @@ struct SendToStreamImpl<char *>
   }
 };
 
+template <>
+struct SendToStreamImpl<double>
+{
+  static void run(std::ostream& stream, double p) {
+    // 13 for ms, 16 of microseconds, plus an extra 2
+    stream.precision(18);
+    stream << p;
+  }
+};
+
 template <>
 struct SendToStreamImpl<JSCustomObject*>
 {

tools/profiler/TableTicker.cpp

@@ -117,7 +117,7 @@ typename Builder::Object TableTicker::GetMetaJSCustomObject(Builder& b)
   b.DefineProperty(meta, "processType", XRE_GetProcessType());
 
   TimeDuration delta = TimeStamp::Now() - sStartTime;
-  b.DefineProperty(meta, "startTime", PR_Now()/1000.0f - delta.ToMilliseconds());
+  b.DefineProperty(meta, "startTime", PR_Now()/1000.0 - delta.ToMilliseconds());
 
   nsresult res;
   nsCOMPtr<nsIHttpProtocolHandler> http = do_GetService(NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "http", &res);