Revert r16648, r16641, r16638 and r16637.

test/cctest/test-platform-linux.cc

Index: test/cctest/test-platform-linux.cc
diff --git a/test/cctest/test-platform-linux.cc b/test/cctest/test-platform-linux.cc
index e0eae026cc7171c696586b27884890fe53a5077e..f289e948284cc1ec2f2e170b70c4063b289177c5 100644
--- a/test/cctest/test-platform-linux.cc
+++ b/test/cctest/test-platform-linux.cc
@@ -39,6 +39,20 @@
 using namespace ::v8::internal;
 
 
+TEST(VirtualMemory) {
+  VirtualMemory* vm = new VirtualMemory(1 * MB);
+  CHECK(vm->IsReserved());
+  void* block_addr = vm->address();
+  size_t block_size = 4 * KB;
+  CHECK(vm->Commit(block_addr, block_size, false));
+  // Check whether we can write to memory.
+  int* addr = static_cast<int*>(block_addr);
+  addr[KB-1] = 2;
+  CHECK(vm->Uncommit(block_addr, block_size));
+  delete vm;
+}
+
+
 TEST(GetCurrentProcessId) {
   CHECK_EQ(static_cast<int>(getpid()), OS::GetCurrentProcessId());
 }