Refactor and cleanup VirtualMemory.

src/mips/codegen-mips.cc

 // Copyright 2012 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 46 matching lines @@
 double fast_exp_simulator(double x) {
   return Simulator::current(Isolate::Current())->CallFP(
       fast_exp_mips_machine_code, x, 0);
 }
 #endif
 
 
 UnaryMathFunction CreateExpFunction() {
   if (!FLAG_fast_math) return &exp;
   size_t actual_size;
-  byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
+  byte* buffer = static_cast<byte*>(VirtualMemory::AllocateRegion(
+          1 * KB, &actual_size, VirtualMemory::EXECUTABLE));
   if (buffer == NULL) return &exp;
   ExternalReference::InitializeMathExpData();
 
   MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
 
   {
     DoubleRegister input = f12;
     DoubleRegister result = f0;
     DoubleRegister double_scratch1 = f4;
     DoubleRegister double_scratch2 = f6;
@@ skipping 17 matching lines @@
       __ Move(v0, v1, result);
     }
     __ Ret();
   }
 
   CodeDesc desc;
   masm.GetCode(&desc);
   ASSERT(!RelocInfo::RequiresRelocation(desc));
 
   CPU::FlushICache(buffer, actual_size);
-  OS::ProtectCode(buffer, actual_size);
+  bool result = VirtualMemory::WriteProtectRegion(buffer, actual_size);
+  ASSERT(result);
+  USE(result);
 
 #if !defined(USE_SIMULATOR)
   return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #else
   fast_exp_mips_machine_code = buffer;
   return &fast_exp_simulator;
 #endif
 }
 
 
@@ skipping 543 matching lines @@
     patcher.masm()->dd(reinterpret_cast<uint32_t>(stub->instruction_start()));
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS