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 <map>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #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 {
 
 // 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.
+  // On errors, an invalid GURL is returned.
+  void ResolveToContentUrl(const base::FilePath& path,
+                           const ResolveToContentUrlCallback& callback);
+
  private:
   // Thin representation of a document in documents provider.
   struct ThinDocument {
     std::string document_id;
     bool is_directory;
   };
 
   // Mapping from a file name to a ThinDocument.
   using NameToThinDocumentMap =
       std::map<base::FilePath::StringType, ThinDocument>;
 
   using ResolveToDocumentIdCallback =
       base::Callback<void(const std::string& document_id)>;
   using ReadDirectoryInternalCallback =
       base::Callback<void(base::File::Error error,
                           NameToThinDocumentMap mapping)>;
 
   void GetFileInfoWithDocumentId(const GetFileInfoCallback& callback,
                                  const std::string& document_id);
   void GetFileInfoWithDocument(const GetFileInfoCallback& callback,
                                mojom::DocumentPtr document);
 
   void ReadDirectoryWithDocumentId(const ReadDirectoryCallback& callback,
                                    const std::string& document_id);
   void ReadDirectoryWithNameToThinDocumentMap(
       const ReadDirectoryCallback& callback,
       base::File::Error error,
       NameToThinDocumentMap mapping);
 
+  void ResolveToContentUrlWithDocumentId(
+      const ResolveToContentUrlCallback& callback,
+      const std::string& document_id);
+
   // Resolves |path| to a document ID. Failures are indicated by an empty
   // document ID.
   void ResolveToDocumentId(const base::FilePath& path,
                            const ResolveToDocumentIdCallback& callback);
   void ResolveToDocumentIdRecursively(
       const std::string& document_id,
       const std::vector<base::FilePath::StringType>& components,
       const ResolveToDocumentIdCallback& callback);
   void ResolveToDocumentIdRecursivelyWithNameToThinDocumentMap(
       const std::vector<base::FilePath::StringType>& components,
@@ skipping 12 matching lines @@
   const std::string authority_;
   const std::string root_document_id_;
   base::WeakPtrFactory<ArcDocumentsProviderRoot> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcDocumentsProviderRoot);
 };
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_ROOT_H_