Use a random seed for the string hash algorithm.

src/isolate.h

 // Copyright 2011 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 895 matching lines @@
     return &regexp_macro_assembler_canonicalize_;
   }
 
   RegExpStack* regexp_stack() { return regexp_stack_; }
 
   unibrow::Mapping<unibrow::Ecma262Canonicalize>*
       interp_canonicalize_mapping() {
     return &interp_canonicalize_mapping_;
   }
 
+  uint32_t HasherSeed() {
+    if (FLAG_randomize_string_hashes) {
+      ASSERT(hasher_seed_ != 0);
+    }
+    return hasher_seed_;
+  }
+
   void* PreallocatedStorageNew(size_t size);
   void PreallocatedStorageDelete(void* p);
   void PreallocatedStorageInit(size_t size);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   Debugger* debugger() {
     if (!NoBarrier_Load(&debugger_initialized_)) InitializeDebugger();
     return debugger_;
   }
   Debug* debug() {
@@ skipping 241 matching lines @@
   unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize_;
   unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange_;
   StringInputBuffer objects_string_compare_buffer_a_;
   StringInputBuffer objects_string_compare_buffer_b_;
   StaticResource<StringInputBuffer> objects_string_input_buffer_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize>
       regexp_macro_assembler_canonicalize_;
   RegExpStack* regexp_stack_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
   void* embedder_data_;
+  uint32_t hasher_seed_;
 
 #if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   bool simulator_initialized_;
   HashMap* simulator_i_cache_;
   Redirection* simulator_redirection_;
 #endif
 
 #ifdef DEBUG
   // A static array of histogram info for each type.
@@ skipping 179 matching lines @@
 
 // Mark the global context with out of memory.
 inline void Context::mark_out_of_memory() {
   global_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_