[inspector] restore provisional breakpoints smarter

src/inspector/v8-debugger-script.h

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 41 matching lines @@
       v8::Local<v8::debug::WasmScript> underlyingScript, String16 id,
       String16 url, String16 source);
 
   virtual ~V8DebuggerScript();
 
   const String16& scriptId() const { return m_id; }
   const String16& url() const { return m_url; }
   bool hasSourceURL() const { return !m_sourceURL.isEmpty(); }
   const String16& sourceURL() const;
   virtual const String16& sourceMappingURL() const = 0;
-  virtual String16 source(v8::Isolate*) const { return m_source; }
-  const String16& hash(v8::Isolate*) const;
+  virtual String16 source() const { return m_source; }
+  const String16& hash() const;
   int startLine() const { return m_startLine; }
   int startColumn() const { return m_startColumn; }
   int endLine() const { return m_endLine; }
   int endColumn() const { return m_endColumn; }
   int executionContextId() const { return m_executionContextId; }
   virtual bool isLiveEdit() const = 0;
   virtual bool isModule() const = 0;
 
   void setSourceURL(const String16&);
   virtual void setSourceMappingURL(const String16&) = 0;
   virtual void setSource(v8::Local<v8::String> source) {
     m_source = toProtocolString(source);
+    m_lineEndings.reset(nullptr);
   }
 
+  String16 lineAt(int lineNumberWithOffset, int maxLength);
+
   virtual bool getPossibleBreakpoints(
       const v8::debug::Location& start, const v8::debug::Location& end,
       std::vector<v8::debug::Location>* locations) = 0;
   virtual void resetBlackboxedStateCache() = 0;
 
  protected:
   V8DebuggerScript(v8::Isolate*, String16 id, String16 url);
 
   String16 m_id;
   String16 m_url;
   String16 m_sourceURL;
   String16 m_source;
   mutable String16 m_hash;
   int m_startLine = 0;
   int m_startColumn = 0;
   int m_endLine = 0;
   int m_endColumn = 0;
   int m_executionContextId = 0;
 
+  std::unique_ptr<std::vector<size_t>> m_lineEndings;
+
   v8::Isolate* m_isolate;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(V8DebuggerScript);
 };
 
 }  // namespace v8_inspector
 
 #endif  // V8_INSPECTOR_V8DEBUGGERSCRIPT_H_