Refactor some source position info

src/debug-delay.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 419 matching lines @@
 Debug.assembler = function(f) {
   if (!IS_FUNCTION(f)) throw new Error('Parameters have wrong types.');
   return %FunctionGetAssemblerCode(f);
 };
 
 Debug.sourcePosition = function(f) {
   if (!IS_FUNCTION(f)) throw new Error('Parameters have wrong types.');
   return %FunctionGetScriptSourcePosition(f);
 };
 
-Debug.findFunctionSourcePosition = function(func, opt_line, opt_column) {
+
+Debug.findFunctionSourceLocation = function(func, opt_line, opt_column) {
   var script = %FunctionGetScript(func);
   var script_offset = %FunctionGetScriptSourcePosition(func);
-  return script.locationFromLine(opt_line, opt_column, script_offset).position;
+  return script.locationFromLine(opt_line, opt_column, script_offset);
 }
 
 
 // Returns the character position in a script based on a line number and an
 // optional position within that line.
 Debug.findScriptSourcePosition = function(script, opt_line, opt_column) {
   var location = script.locationFromLine(opt_line, opt_column);  
   return location ? location.position : null;
 }
 
@@ skipping 17 matching lines @@
   }
 };
 
 
 Debug.setBreakPoint = function(func, opt_line, opt_column, opt_condition) {
   if (!IS_FUNCTION(func)) throw new Error('Parameters have wrong types.');
   // Break points in API functions are not supported.
   if (%FunctionIsAPIFunction(func)) {
     throw new Error('Cannot set break point in native code.');
   }
-  var source_position = this.findFunctionSourcePosition(func, opt_line, opt_column) -
-                        this.sourcePosition(func);
+  // Find source position relative to start of the function
+  var break_position =
+      this.findFunctionSourceLocation(func, opt_line, opt_column).position;
+  var source_position = break_position - this.sourcePosition(func);
   // Find the script for the function.
   var script = %FunctionGetScript(func);
   // Break in builtin JavaScript code is not supported.
   if (script.type == Debug.ScriptType.Native) {
     throw new Error('Cannot set break point in native code.');
   }
   // If the script for the function has a name convert this to a script break
   // point.
   if (script && script.name) {
     // Adjust the source position to be script relative.
@@ skipping 1257 matching lines @@
       json += NumberToJSON_(elem);
     } else if (IS_STRING(elem)) {
       json += StringToJSON_(elem);
     } else {
       json += elem;
     }
   }
   json += ']';
   return json;
 }