Update from chromium https://crrev.com/304586

base/files/file_util_win.cc

Index: base/files/file_util_win.cc
diff --git a/base/files/file_util_win.cc b/base/files/file_util_win.cc
index 733c32c27da220e47d4cab076a89a08430ad6b09..b511d3cc8cd4ab067319558fa6269ecde2a4bbef 100644
--- a/base/files/file_util_win.cc
+++ b/base/files/file_util_win.cc
@@ -210,7 +210,7 @@ bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
                     << target_path.value().c_str();
         success = false;
       }
-    } else if (!internal::CopyFileUnsafe(current, target_path)) {
+    } else if (!CopyFile(current, target_path)) {
       DLOG(ERROR) << "CopyDirectory() couldn't create file: "
                   << target_path.value().c_str();
       success = false;
@@ -722,6 +722,37 @@ int GetMaximumPathComponentLength(const FilePath& path) {
   return std::min(whole_path_limit, static_cast<int>(max_length));
 }
 
+bool CopyFile(const FilePath& from_path, const FilePath& to_path) {
+  ThreadRestrictions::AssertIOAllowed();
+  if (from_path.ReferencesParent() || to_path.ReferencesParent())
+    return false;
+
+  // NOTE: I suspect we could support longer paths, but that would involve
+  // analyzing all our usage of files.
+  if (from_path.value().length() >= MAX_PATH ||
+      to_path.value().length() >= MAX_PATH) {
+    return false;
+  }
+
+  // Unlike the posix implementation that copies the file manually and discards
+  // the ACL bits, CopyFile() copies the complete SECURITY_DESCRIPTOR and access
+  // bits, which is usually not what we want. We can't do much about the
+  // SECURITY_DESCRIPTOR but at least remove the read only bit.
+  const wchar_t* dest = to_path.value().c_str();
+  if (!::CopyFile(from_path.value().c_str(), dest, false)) {
+    // Copy failed.
+    return false;
+  }
+  DWORD attrs = GetFileAttributes(dest);
+  if (attrs == INVALID_FILE_ATTRIBUTES) {
+    return false;
+  }
+  if (attrs & FILE_ATTRIBUTE_READONLY) {
+    SetFileAttributes(dest, attrs & ~FILE_ATTRIBUTE_READONLY);
+  }
+  return true;
+}
+
 // -----------------------------------------------------------------------------
 
 namespace internal {
@@ -760,35 +791,6 @@ bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
   return ret;
 }
 
-bool CopyFileUnsafe(const FilePath& from_path, const FilePath& to_path) {
-  ThreadRestrictions::AssertIOAllowed();
-
-  // NOTE: I suspect we could support longer paths, but that would involve
-  // analyzing all our usage of files.
-  if (from_path.value().length() >= MAX_PATH ||
-      to_path.value().length() >= MAX_PATH) {
-    return false;
-  }
-
-  // Unlike the posix implementation that copies the file manually and discards
-  // the ACL bits, CopyFile() copies the complete SECURITY_DESCRIPTOR and access
-  // bits, which is usually not what we want. We can't do much about the
-  // SECURITY_DESCRIPTOR but at least remove the read only bit.
-  const wchar_t* dest = to_path.value().c_str();
-  if (!::CopyFile(from_path.value().c_str(), dest, false)) {
-    // Copy failed.
-    return false;
-  }
-  DWORD attrs = GetFileAttributes(dest);
-  if (attrs == INVALID_FILE_ATTRIBUTES) {
-    return false;
-  }
-  if (attrs & FILE_ATTRIBUTE_READONLY) {
-    SetFileAttributes(dest, attrs & ~FILE_ATTRIBUTE_READONLY);
-  }
-  return true;
-}
-
 bool CopyAndDeleteDirectory(const FilePath& from_path,
                             const FilePath& to_path) {
   ThreadRestrictions::AssertIOAllowed();