Fix Issue 1320: LiveEdit: text differencer fails with out of memory on large files

src/liveedit.h

 // Copyright 2010 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 117 matching lines @@
     FUNCTION_AVAILABLE_FOR_PATCH = 1,
     FUNCTION_BLOCKED_ON_ACTIVE_STACK = 2,
     FUNCTION_BLOCKED_ON_OTHER_STACK = 3,
     FUNCTION_BLOCKED_UNDER_NATIVE_CODE = 4,
     FUNCTION_REPLACED_ON_ACTIVE_STACK = 5
   };
 
   // Compares 2 strings line-by-line, then token-wise and returns diff in form
   // of array of triplets (pos1, pos1_end, pos2_end) describing list
   // of diff chunks.
-  static Handle<JSArray> CompareStrings(Handle<String> s1,
-                                        Handle<String> s2);
+  static MUST_USE_RESULT MaybeObject/*<JSArray>*/* CompareStrings(
+      Handle<String> s1, Handle<String> s2);
 };
 
 
 // A general-purpose comparator between 2 arrays.
 class Comparator {
  public:
 
   // Holds 2 arrays of some elements allowing to compare any pair of
   // element from the first array and element from the second array.
   class Input {
@@ skipping 11 matching lines @@
    public:
     // Puts another chunk in result list. Note that technically speaking
     // only 3 arguments actually needed with 4th being derivable.
     virtual void AddChunk(int pos1, int pos2, int len1, int len2) = 0;
 
    protected:
     virtual ~Output() {}
   };
 
   // Finds the difference between 2 arrays of elements.
-  static void CalculateDifference(Input* input,
-                                  Output* result_writer);
+  static MUST_USE_RESULT MaybeObject/*<void>*/* CalculateDifference(
+      Input* input, Output* result_writer, Isolate* isolate);
 };
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal
 
 #endif /* V*_LIVEEDIT_H_ */