Add pause/resume for isolates in vmservice/observatory.

runtime/vm/json_stream.cc

Index: runtime/vm/json_stream.cc
diff --git a/runtime/vm/json_stream.cc b/runtime/vm/json_stream.cc
index 57a675d77b2fdd87fc8b35d90bdebe24f5eb0f6d..afbe30e35f91b850c8fb5d3a7f9076bd7cf8bf59 100644
--- a/runtime/vm/json_stream.cc
+++ b/runtime/vm/json_stream.cc
@@ -247,6 +247,12 @@ void JSONStream::PrintValue(SourceBreakpoint* bpt) {
 }
 
 
+void JSONStream::PrintValue(const DebuggerEvent* event) {
+  PrintCommaIfNeeded();
+  event->PrintJSON(this);
+}
+
+
 void JSONStream::PrintValue(Isolate* isolate, bool ref) {
   PrintCommaIfNeeded();
   isolate->PrintJSON(this, ref);
@@ -283,6 +289,18 @@ void JSONStream::PrintProperty(const char* name, const char* s) {
 }
 
 
+void JSONStream::PrintProperty(const char* name, const DebuggerEvent* event) {
+  PrintPropertyName(name);
+  PrintValue(event);
+}
+
+
+void JSONStream::PrintProperty(const char* name, Isolate* isolate) {
+  PrintPropertyName(name);
+  PrintValue(isolate);
+}
+
+
 void JSONStream::PrintfProperty(const char* name, const char* format, ...) {
   PrintPropertyName(name);
   va_list args;