Refactor

This renames the "mock" code to "reference" because that's really what
it is.  Also, some code has been moved from the CDM repo to a common
utility directory so that it can be included here, and the oemcrypto
unit tests can now be built without having access to a current CDM
repo.

There are no functionality changes in this CL.

util/include/file_store.h

@@ -0,0 +1,80 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// File - Platform independent interface for a File class
+//
+#ifndef WVCDM_UTIL_FILE_STORE_H_
+#define WVCDM_UTIL_FILE_STORE_H_
+
+#include <unistd.h>
+#include <string>
+#include <vector>
+
+#include "disallow_copy_and_assign.h"
+
+namespace wvcdm {
+
+// File class. The implementation is platform dependent.
+class File {
+ public:
+  virtual ssize_t Read(char* buffer, size_t bytes);
+  virtual ssize_t Write(const char* buffer, size_t bytes);
+  virtual void Close();
+
+ protected:
+  class Impl;
+
+  File(Impl*);
+  virtual ~File();
+
+ private:
+  Impl* impl_;
+
+  friend class FileSystem;
+  CORE_DISALLOW_COPY_AND_ASSIGN(File);
+};
+
+class FileSystem {
+ public:
+  class Impl;
+
+  // defines as bit flag
+  enum OpenFlags {
+    kNoFlags = 0,
+    kCreate = 1,
+    kReadOnly = 2,  // defaults to read and write access
+    kTruncate = 4
+  };
+
+  FileSystem();
+  FileSystem(const std::string& origin, void* extra_data);
+  virtual ~FileSystem();
+
+  virtual File* Open(const std::string& file_path, int flags);
+
+  virtual bool Exists(const std::string& file_path);
+  virtual bool Remove(const std::string& file_path);
+  virtual ssize_t FileSize(const std::string& file_path);
+
+  // Return the filenames stored at dir_path.
+  // dir_path will be stripped from the returned names.
+  virtual bool List(const std::string& dir_path,
+                    std::vector<std::string>* names);
+
+  const std::string& origin() const { return origin_; }
+  void SetOrigin(const std::string& origin);
+
+  const std::string& identifier() const { return identifier_; }
+  void SetIdentifier(const std::string& identifier);
+  bool IsGlobal() const { return identifier_.empty(); }
+
+ private:
+  Impl* impl_;
+  std::string origin_;
+  std::string identifier_;
+
+  CORE_DISALLOW_COPY_AND_ASSIGN(FileSystem);
+};
+
+}  // namespace wvcdm
+
+#endif  // WVCDM_UTIL_FILE_STORE_H_