mediaview: Mount ARC documents provider file system volumes.

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

Index: chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h
index 38ae3c862f013b4c615109d9af815893af89dd85..3c9de2a3c2fe9ab833a5d66885c575f816e2c752 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h
+++ b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h
@@ -29,6 +29,12 @@ extern const base::FilePath::CharType kDocumentsProviderMountPointPath[];
 // Defined as DocumentsContract.Document.MIME_TYPE_DIR in Android.
 extern const char kAndroidDirectoryMimeType[];
 
+// Returns the path of a directory where the specified DocumentsProvider is
+// mounted.
+base::FilePath GetDocumentsProviderMountPath(
+    const std::string& authority,
+    const std::string& root_document_id);
+
 // Parses a FileSystemURL pointing to ARC documents provider file system.
 // On success, true is returned. All arguments must not be nullptr.
 bool ParseDocumentsProviderUrl(const storage::FileSystemURL& url,