Use latent breakpoints list when looking up or removing breakpoints.

runtime/vm/debugger.h

Index: runtime/vm/debugger.h
diff --git a/runtime/vm/debugger.h b/runtime/vm/debugger.h
index 9bf4d969dfa8ffd4eb96a81274ec0ac9c8b92a34..d49e3acabbaca8cc29437fd3b757e43a53aec188 100644
--- a/runtime/vm/debugger.h
+++ b/runtime/vm/debugger.h
@@ -487,7 +487,6 @@ class Debugger {
                                                   intptr_t line_number,
                                                   intptr_t column_number);
 
-
   void RemoveBreakpoint(intptr_t bp_id);
   Breakpoint* GetBreakpointById(intptr_t id);
 
@@ -643,6 +642,8 @@ class Debugger {
                                     TokenPosition last_token_pos,
                                     intptr_t requested_line,
                                     intptr_t requested_column);
+  bool RemoveBreakpointFromTheList(intptr_t bp_id, BreakpointLocation** list);
+  Breakpoint* GetBreakpointByIdInTheList(intptr_t id, BreakpointLocation* list);
   void RemoveUnlinkedCodeBreakpoints();
   void UnlinkCodeBreakpoints(BreakpointLocation* bpt_location);
   BreakpointLocation* GetLatentBreakpoint(const String& url,
@@ -658,6 +659,8 @@ class Debugger {
   CodeBreakpoint* GetCodeBreakpoint(uword breakpoint_address);
 
   void SyncBreakpointLocation(BreakpointLocation* loc);
+  void PrintBreakpointsListToJSONArray(BreakpointLocation* sbpt,
+                                       JSONArray* jsarr) const;
 
   ActivationFrame* TopDartFrame() const;
   static ActivationFrame* CollectDartFrame(