[debugger] introduce abstract interface for break location.

src/interpreter/source-position-table.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INTERPRETER_SOURCE_POSITION_TABLE_H_
 #define V8_INTERPRETER_SOURCE_POSITION_TABLE_H_
 
 #include "src/assert-scope.h"
 #include "src/handles.h"
 #include "src/zone.h"
@@ skipping 30 matching lines @@
   }
 
   Isolate* isolate_;
   ZoneVector<Entry> entries_;
 };
 
 class SourcePositionTableIterator {
  public:
   explicit SourcePositionTableIterator(BytecodeArray* bytecode_array);
 
-  static int PositionFromBytecodeOffset(BytecodeArray* bytecode_array,
-                                        int bytecode_offset);
   void Advance();
 
   int bytecode_offset() const {
     DCHECK(!done());
     return bytecode_offset_;
   }
   int source_position() const {
     DCHECK(!done());
     return source_position_;
   }
@@ skipping 11 matching lines @@
   int bytecode_offset_;
   int source_position_;
   DisallowHeapAllocation no_gc;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_SOURCE_POSITION_TABLE_H_