[debugger] use source position to identify break points.

src/debug/debug.h

Index: src/debug/debug.h
diff --git a/src/debug/debug.h b/src/debug/debug.h
index b721f142f87e70dbf2f74b2f707328cd80c22c34..4bfb8a9a2a1231ac05cc473e9aa0545be43c4f9b 100644
--- a/src/debug/debug.h
+++ b/src/debug/debug.h
@@ -75,6 +75,7 @@ class BreakLocation {
                                       int statement_position,
                                       List<BreakLocation>* result_out);
 
+  // Find break location (for a break point) from source positon.
   static BreakLocation FromPosition(Handle<DebugInfo> debug_info, int position,
                                     BreakPositionAlignment alignment);
 
@@ -89,9 +90,8 @@ class BreakLocation {
   inline bool IsDebuggerStatement() const {
     return type_ == DEBUGGER_STATEMENT;
   }
-  inline bool HasBreakPoint() const {
-    return debug_info_->HasBreakPoint(code_offset_);
-  }
+
+  bool HasBreakPoint() const;
 
   Handle<Object> BreakPointObjects() const;