Implement deletion of breakpoints

runtime/vm/debugger.h

Index: runtime/vm/debugger.h
===================================================================
--- runtime/vm/debugger.h	(revision 3467)
+++ runtime/vm/debugger.h	(working copy)
@@ -23,6 +23,7 @@
 
   RawFunction* function() const { return function_; }
   uword pc() const { return pc_; }
+  intptr_t token_index() const { return token_index_; }
 
   RawScript* SourceCode();
   RawString* SourceUrl();
@@ -33,11 +34,13 @@
 
   void set_next(Breakpoint* value) { next_ = value; }
   Breakpoint* next() const { return this->next_; }
+  intptr_t pc_desc_index() const { return pc_desc_index_; }
 
   RawFunction* function_;
   intptr_t pc_desc_index_;
   intptr_t token_index_;
   uword pc_;
+  uword saved_bytes_;
   intptr_t line_number_;
   Breakpoint* next_;
 
@@ -114,8 +117,10 @@
 class Debugger {
  public:
   Debugger();
+  ~Debugger();
 
   void Initialize(Isolate* isolate);
+  void Shutdown();
   bool IsActive();
 
   void SetBreakpointHandler(BreakpointHandler* handler);
@@ -129,6 +134,8 @@
   Breakpoint* SetBreakpointAtLine(const String& script_url,
                                   intptr_t line_number);
 
+  void RemoveBreakpoint(Breakpoint* bpt);
+
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
   // Returns NULL if no breakpoint exists for the given address.
@@ -143,7 +150,11 @@
  private:
   Breakpoint* SetBreakpoint(const Function& target_function,
                             intptr_t token_index);
-  void AddBreakpoint(Breakpoint* bpt);
+  void UnsetBreakpoint(Breakpoint* bpt);
+  Breakpoint* NewBreakpoint(const Function& func, intptr_t pc_desc_index);
+  void RegisterBreakpoint(Breakpoint* bpt);
+  Breakpoint* GetBreakpointByFunction(const Function& func,
+                                      intptr_t token_index);
 
   bool initialized_;
   BreakpointHandler* bp_handler_;