Revert r16648, r16641, r16638 and r16637.

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index faf7b54d43a139139d37789afca4ce46eb639c24..1bcf3e3a605b051571dc9c51912264c65b90e14e 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -64,8 +64,7 @@ double fast_exp_simulator(double x) {
 UnaryMathFunction CreateExpFunction() {
   if (!FLAG_fast_math) return &exp;
   size_t actual_size;
-  byte* buffer = static_cast<byte*>(VirtualMemory::AllocateRegion(
-          1 * KB, &actual_size, VirtualMemory::EXECUTABLE));
+  byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
   if (buffer == NULL) return &exp;
   ExternalReference::InitializeMathExpData();
 
@@ -103,9 +102,7 @@ UnaryMathFunction CreateExpFunction() {
   ASSERT(!RelocInfo::RequiresRelocation(desc));
 
   CPU::FlushICache(buffer, actual_size);
-  bool result = VirtualMemory::WriteProtectRegion(buffer, actual_size);
-  ASSERT(result);
-  USE(result);
+  OS::ProtectCode(buffer, actual_size);
 
 #if !defined(USE_SIMULATOR)
   return FUNCTION_CAST<UnaryMathFunction>(buffer);
@@ -125,8 +122,7 @@ OS::MemCopyUint8Function CreateMemCopyUint8Function(
     return stub;
   }
   size_t actual_size;
-  byte* buffer = static_cast<byte*>(VirtualMemory::AllocateRegion(
-          1 * KB, &actual_size, VirtualMemory::EXECUTABLE));
+  byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
   if (buffer == NULL) return stub;
 
   MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
@@ -268,9 +264,7 @@ OS::MemCopyUint8Function CreateMemCopyUint8Function(
   ASSERT(!RelocInfo::RequiresRelocation(desc));
 
   CPU::FlushICache(buffer, actual_size);
-  bool result = VirtualMemory::WriteProtectRegion(buffer, actual_size);
-  ASSERT(result);
-  USE(result);
+  OS::ProtectCode(buffer, actual_size);
   return FUNCTION_CAST<OS::MemCopyUint8Function>(buffer);
 #endif
 }
@@ -286,8 +280,7 @@ OS::MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
     return stub;
   }
   size_t actual_size;
-  byte* buffer = static_cast<byte*>(VirtualMemory::AllocateRegion(
-          1 * KB, &actual_size, VirtualMemory::EXECUTABLE));
+  byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
   if (buffer == NULL) return stub;
 
   MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
@@ -359,9 +352,7 @@ OS::MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
   masm.GetCode(&desc);
 
   CPU::FlushICache(buffer, actual_size);
-  bool result = VirtualMemory::WriteProtectRegion(buffer, actual_size);
-  ASSERT(result);
-  USE(result);
+  OS::ProtectCode(buffer, actual_size);
 
   return FUNCTION_CAST<OS::MemCopyUint16Uint8Function>(buffer);
 #endif