Fix overly-strict parameter checking of _getCallSiteData.

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index 342c1a4b1b215a8c5f1ea19035f878dbf70d913e..09676cc1abc6aa4eb08becc1a6e8db51cf4a82f1 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -1969,6 +1969,7 @@ static bool GetHitsOrSites(Isolate* isolate, JSONStream* js, bool as_sites) {
 
 static const MethodParameter* get_coverage_params[] = {
   ISOLATE_PARAMETER,
+  new IdParameter("targetId", false),
   NULL,
 };
 
@@ -1981,7 +1982,7 @@ static bool GetCoverage(Isolate* isolate, JSONStream* js) {
 
 static const MethodParameter* get_call_site_data_params[] = {
   ISOLATE_PARAMETER,
-  new IdParameter("targetId", true),
+  new IdParameter("targetId", false),
   NULL,
 };