Support column-based breakpoints in the VM and Observatory.

runtime/vm/json_stream.h

Index: runtime/vm/json_stream.h
diff --git a/runtime/vm/json_stream.h b/runtime/vm/json_stream.h
index cdc5c4ec6046cfdcb7a84b5f4350551f30d06f7e..f835edc3055c85d86f649e65c762679ee0be98b3 100644
--- a/runtime/vm/json_stream.h
+++ b/runtime/vm/json_stream.h
@@ -15,6 +15,7 @@ namespace dart {
 
 class Array;
 class Breakpoint;
+class BreakpointLocation;
 class Field;
 class GrowableObjectArray;
 class Instance;
@@ -209,7 +210,11 @@ class JSONObject : public ValueObject {
 
   void AddLocation(const Script& script,
                    intptr_t token_pos,
-                   intptr_t end_token_pos = -1);
+                   intptr_t end_token_pos = -1) const;
+
+  void AddLocation(const BreakpointLocation* bpt_loc) const;
+
+  void AddUnresolvedLocation(const BreakpointLocation* bpt_loc) const;
 
   void AddProperty(const char* name, bool b) const {
     stream_->PrintPropertyBool(name, b);