Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)

Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}
diff --git a/webrtc/rtc_base/win32filesystem.h b/webrtc/rtc_base/win32filesystem.h
new file mode 100644
index 0000000..f7a6ab4
--- /dev/null
+++ b/webrtc/rtc_base/win32filesystem.h
@@ -0,0 +1,64 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_WIN32FILESYSTEM_H_
+#define WEBRTC_RTC_BASE_WIN32FILESYSTEM_H_
+
+#include "fileutils.h"
+
+namespace rtc {
+
+class Win32Filesystem : public FilesystemInterface {
+ public:
+  // This will attempt to delete the path located at filename.
+  // If the path points to a folder, it will fail with VERIFY
+  bool DeleteFile(const Pathname& filename) override;
+
+  // Creates a directory. This will call itself recursively to create /foo/bar even if
+  // /foo does not exist.
+  // Returns TRUE if function succeeds
+  bool CreateFolder(const Pathname& pathname) override;
+
+  // This moves a file from old_path to new_path. If the new path is on a
+  // different volume than the old, it will attempt to copy and then delete
+  // the folder
+  // Returns true if the file is successfully moved
+  bool MoveFile(const Pathname& old_path, const Pathname& new_path) override;
+
+  // Returns true if a pathname is a directory
+  bool IsFolder(const Pathname& pathname) override;
+
+  // Returns true if a file exists at path
+  bool IsFile(const Pathname& path) override;
+
+  // Returns true if pathname refers to no filesystem object, every parent
+  // directory either exists, or is also absent.
+  bool IsAbsent(const Pathname& pathname) override;
+
+  // All of the following functions set pathname and return true if successful.
+  // Returned paths always include a trailing backslash.
+  // If create is true, the path will be recursively created.
+  // If append is non-null, it will be appended (and possibly created).
+
+  std::string TempFilename(const Pathname& dir,
+                           const std::string& prefix) override;
+
+  bool GetFileSize(const Pathname& path, size_t* size) override;
+
+  // A folder appropriate for storing temporary files (Contents are
+  // automatically deleted when the program exists)
+  bool GetTemporaryFolder(Pathname& path,
+                          bool create,
+                          const std::string* append) override;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_WIN32FILESYSTEM_H_