mojo leveldb: Address some comments that came after it was put in the CQ.

components/filesystem/directory_impl.cc

Index: components/filesystem/directory_impl.cc
diff --git a/components/filesystem/directory_impl.cc b/components/filesystem/directory_impl.cc
index 58480a18a1fb70ac9faf042ceef83ccd8fb31521..e8fab2a861b4beba9838fbb6ad2a4f22bffa7968 100644
--- a/components/filesystem/directory_impl.cc
+++ b/components/filesystem/directory_impl.cc
@@ -68,25 +68,7 @@ void DirectoryImpl::OpenFile(const mojo::String& raw_path,
     return;
   }
 
-#if defined(OS_WIN)
-  // On Windows, FILE_FLAG_BACKUP_SEMANTICS is needed to open a directory.
-  if (base::DirectoryExists(path))
-    open_flags |= base::File::FLAG_BACKUP_SEMANTICS;
-#endif  // OS_WIN
-
-  base::File base_file(path, open_flags);
-  if (!base_file.IsValid()) {
-    callback.Run(GetError(base_file));
-    return;
-  }
-
-  base::File::Info info;
-  if (!base_file.GetInfo(&info)) {
-    callback.Run(FileError::FAILED);
-    return;
-  }
-
-  if (info.is_directory) {
+  if (base::DirectoryExists(path)) {
     // We must not return directories as files. In the file abstraction, we can
     // fetch raw file descriptors over mojo pipes, and passing a file
     // descriptor to a directory is a sandbox escape on Windows.
@@ -94,6 +76,12 @@ void DirectoryImpl::OpenFile(const mojo::String& raw_path,
     return;
   }
 
+  base::File base_file(path, open_flags);
+  if (!base_file.IsValid()) {
+    callback.Run(GetError(base_file));
+    return;
+  }
+
   if (file.is_pending()) {
     new FileImpl(std::move(file), path, std::move(base_file), lock_table_);
   }
@@ -110,25 +98,7 @@ void DirectoryImpl::OpenFileHandle(const mojo::String& raw_path,
     return;
   }
 
-#if defined(OS_WIN)
-  // On Windows, FILE_FLAG_BACKUP_SEMANTICS is needed to open a directory.
-  if (base::DirectoryExists(path))
-    open_flags |= base::File::FLAG_BACKUP_SEMANTICS;
-#endif  // OS_WIN
-
-  base::File base_file(path, open_flags);
-  if (!base_file.IsValid()) {
-    callback.Run(GetError(base_file), ScopedHandle());
-    return;
-  }
-
-  base::File::Info info;
-  if (!base_file.GetInfo(&info)) {
-    callback.Run(FileError::FAILED, ScopedHandle());
-    return;
-  }
-
-  if (info.is_directory) {
+  if (base::DirectoryExists(path)) {
     // We must not return directories as files. In the file abstraction, we can
     // fetch raw file descriptors over mojo pipes, and passing a file
     // descriptor to a directory is a sandbox escape on Windows.
@@ -136,6 +106,12 @@ void DirectoryImpl::OpenFileHandle(const mojo::String& raw_path,
     return;
   }
 
+  base::File base_file(path, open_flags);
+  if (!base_file.IsValid()) {
+    callback.Run(GetError(base_file), ScopedHandle());
+    return;
+  }
+
   MojoHandle mojo_handle;
   MojoResult create_result = MojoCreatePlatformHandleWrapper(
       base_file.TakePlatformFile(), &mojo_handle);