Implement the memory mapped file class for posix.

base/file_util_win.cc

Index: base/file_util_win.cc
===================================================================
--- base/file_util_win.cc	(revision 6919)
+++ base/file_util_win.cc	(working copy)
@@ -704,22 +704,6 @@
       length_(INVALID_FILE_SIZE) {
 }
 
-MemoryMappedFile::~MemoryMappedFile() {
-  CloseHandles();
-}
-
-bool MemoryMappedFile::Initialize(const FilePath& file_name) {
-  if (IsValid())
-    return false;
-
-  if (!MapFileToMemory(file_name)) {
-    CloseHandles();
-    return false;
-  }
-
-  return true;
-}
-
 bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
   file_ = ::CreateFile(file_name.value().c_str(), GENERIC_READ,
                        FILE_SHARE_READ, NULL, OPEN_EXISTING,
@@ -741,10 +725,6 @@
   return data_ != NULL;
 }
 
-bool MemoryMappedFile::IsValid() {
-  return data_ != NULL;
-}
-
 void MemoryMappedFile::CloseHandles() {
   if (data_)
     ::UnmapViewOfFile(data_);