mediaview: Implement ArcDocumentsProviderBackendDelegate.

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

 // 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.
 
 #include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
 
 #include <vector>
 
 #include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "net/base/escape.h"
 #include "storage/browser/fileapi/file_system_url.h"
+#include "url/gurl.h"
 
 namespace arc {
 
 const char kDocumentsProviderMountPointName[] = "arc-documents-provider";
 const base::FilePath::CharType kDocumentsProviderMountPointPath[] =
     "/special/arc-documents-provider";
 const char kAndroidDirectoryMimeType[] = "vnd.android.document/directory";
 
 bool ParseDocumentsProviderUrl(const storage::FileSystemURL& url,
                                std::string* authority,
@@ skipping 24 matching lines @@
   // Special case: AppendRelativePath() fails for identical paths.
   if (url_path_stripped == root_path) {
     path->clear();
   } else {
     bool success = root_path.AppendRelativePath(url_path_stripped, path);
     DCHECK(success);
   }
   return true;
 }
 
+GURL BuildDocumentUrl(const std::string& authority,
+                      const std::string& document_id) {
+  return GURL(base::StringPrintf(
+      "content://%s/document/%s",
+      net::EscapeQueryParamValue(authority, false /* use_plus */).c_str(),
+      net::EscapeQueryParamValue(document_id, false /* use_plus */).c_str()));
+}
+
 }  // namespace arc