Add an API to get total size of Drive cache including non-evictable ones.

components/drive/chromeos/fake_file_system.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_DRIVE_CHROMEOS_FAKE_FILE_SYSTEM_H_
 #define COMPONENTS_DRIVE_CHROMEOS_FAKE_FILE_SYSTEM_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 112 matching lines @@
   void SetProperty(const base::FilePath& drive_file_path,
                    google_apis::drive::Property::Visibility visibility,
                    const std::string& key,
                    const std::string& value,
                    const FileOperationCallback& callback) override;
   void Reset(const FileOperationCallback& callback) override;
   void GetPathFromResourceId(const std::string& resource_id,
                              const GetFilePathCallback& callback) override;
   void FreeDiskSpaceIfNeededFor(int64_t num_bytes,
                                 const FreeDiskSpaceCallback& callback) override;
-  void CalculateEvictableCacheSize(
-      const EvictableCacheSizeCallback& callback) override;
+  void CalculateCacheSize(const CacheSizeCallback& callback) override;
+  void CalculateEvictableCacheSize(const CacheSizeCallback& callback) override;
 
  private:
   // Helpers of GetFileContent.
   // How the method works:
   // 1) Gets ResourceEntry of the path.
   // 2) Look at if there is a cache file or not. If found return it.
   // 3) Otherwise start DownloadFile.
   // 4) Runs the |completion_callback| upon the download completion.
   void GetFileContentAfterGetResourceEntry(
       const GetFileContentInitializedCallback& initialized_callback,
@@ skipping 45 matching lines @@
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<FakeFileSystem> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeFileSystem);
 };
 
 }  // namespace test_util
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_CHROMEOS_FAKE_FILE_SYSTEM_H_