Download WebAPK into a WebAPK-specifc directory, and delete all cached ones.

chrome/browser/android/webapk/webapk_installer.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_ANDROID_WEBAPK_WEBAPK_INSTALLER_H_
 #define CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INSTALLER_H_
 
 #include <jni.h>
 #include <memory>
 
@@ skipping 131 matching lines @@
   // WebAPK.
   void SendRequest(std::unique_ptr<webapk::WebApk> request_proto,
                    net::URLFetcher::RequestType request_type,
                    const GURL& server_url);
 
   // Called with the URL of generated WebAPK and the package name that the
   // WebAPK should be installed at.
   void OnGotWebApkDownloadUrl(const GURL& download_url,
                               const std::string& package_name);
 
+  // Called once the sub directory to store the downloaded WebAPK was
+  // created with permissions set properly or if creation failed.
+  void OnCreatedSubDirAndSetPermissions(const GURL& download_url,
+                                        const base::FilePath& file_path);
+
   // Called once the WebAPK has been downloaded. Makes the downloaded WebAPK
   // world readable and installs the WebAPK if the download was successful.
   // |file_path| is the file path that the WebAPK was downloaded to.
   void OnWebApkDownloaded(const base::FilePath& file_path,
                           FileDownloader::Result result);
 
   // Called once the downloaded WebAPK has been made world readable. Installs
   // the WebAPK.
   // |file_path| is the file path that the WebAPK was downloaded to.
   // |change_permission_success| is whether the WebAPK could be made world
@@ skipping 61 matching lines @@
   // Points to the Java Object.
   base::android::ScopedJavaGlobalRef<jobject> java_ref_;
 
   // Used to get |weak_ptr_|.
   base::WeakPtrFactory<WebApkInstaller> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebApkInstaller);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INSTALLER_H_