mediaview: Implement ArcDocumentsProviderBackendDelegate.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h

 // Copyright 2016 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 CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/optional.h"
 #include "components/arc/common/file_system.mojom.h"
 #include "storage/browser/fileapi/async_file_util.h"
 
+class GURL;
+
 namespace arc {
 
 class ArcDocumentsProviderDocument;
 
 // Represents a file system root in Android Documents Provider.
 //
 // All methods must be called on the IO thread.
 // If this object is deleted while there are in-flight operations, callbacks
 // for those operations will be never called.
 class ArcDocumentsProviderRoot {
  public:
   using GetFileInfoCallback = storage::AsyncFileUtil::GetFileInfoCallback;
   using ReadDirectoryCallback = storage::AsyncFileUtil::ReadDirectoryCallback;
+  using ResolveToContentUrlCallback =
+      base::Callback<void(const GURL& content_url)>;
 
   ArcDocumentsProviderRoot(const std::string& authority,
                            const std::string& root_document_id);
   ~ArcDocumentsProviderRoot();
 
   // Queries information of a file just like AsyncFileUtil.GetFileInfo().
   void GetFileInfo(const base::FilePath& path,
                    const GetFileInfoCallback& callback);
 
   // Queries a list of files under a directory just like
   // AsyncFileUtil.ReadDirectory().
   void ReadDirectory(const base::FilePath& path,
                      const ReadDirectoryCallback& callback);
 
+  // Resolves a file path into a content:// URL pointing to the file
+  // on DocumentsProvider. Returns URL that can be passed to
+  // ArcContentFileSystemFileSystemReader to read the content.
+  void ResolveToContentUrl(const base::FilePath& path,
+                           const ResolveToContentUrlCallback& callback);
+
  private:
   void GetFileInfoAfterCacheUpdate(const base::FilePath& path,
                                    const GetFileInfoCallback& callback);
   void GetFileInfoWithDocument(const GetFileInfoCallback& callback,
                                mojom::DocumentPtr document);
 
   void ReadDirectoryAfterCacheUpdate(const base::FilePath& path,
                                      const ReadDirectoryCallback& callback);
   void ReadDirectoryWithChildDocuments(
       const base::FilePath& path,
       const ReadDirectoryCallback& callback,
       base::Optional<std::vector<mojom::DocumentPtr>> children);
 
+  void ResolveToContentUrlAfterCacheUpdate(
+      const base::FilePath& path,
+      const ResolveToContentUrlCallback& callback);
+
   void UpdateDirectoryCacheUpTo(const base::FilePath& path,
                                 const base::Closure& callback);
   void UpdateDirectoryCacheIter(const base::FilePath& parent_directory_path,
                                 const base::FilePath& remaining_path,
                                 const base::Closure& callback);
   void UpdateDirectoryCacheIterWithChildDocuments(
       const base::FilePath& parent_directory_path,
       const base::FilePath& remaining_path,
       const base::Closure& callback,
       base::Optional<std::vector<mojom::DocumentPtr>> children);
 
   const std::string authority_;
   const std::unique_ptr<ArcDocumentsProviderDocument> root_directory_;
   base::WeakPtrFactory<ArcDocumentsProviderRoot> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcDocumentsProviderRoot);
 };
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_