Remove untrusted sources installation flow.

chrome/browser/android/webapk/webapk_install_service.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_INSTALL_SERVICE_H_
 #define CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INSTALL_SERVICE_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 10 matching lines @@
 
 struct ShortcutInfo;
 class SkBitmap;
 
 // A Java counterpart will be generated for this enum.
 // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser.webapps
 enum class WebApkInstallResult {
   SUCCESS = 0,
   FAILURE = 1,
   // An install was initiated but it timed out. We did not get a response from
-  // Google Play (or the Android OS in the case of the "unknown sources" flow)
-  // so it is possible that the install will complete some time in the future.
+  // the install service so it is possible that the install will complete some
+  // time in the future.
   PROBABLE_FAILURE = 2
 };
 
 // Service which talks to Chrome WebAPK server and Google Play to generate a
 // WebAPK on the server, download it, and install it.
 class WebApkInstallService : public KeyedService {
  public:
   // Called when the creation/updating of a WebAPK is finished or failed.
   // Parameters:
   // - the result of the installation.
@@ skipping 43 matching lines @@
   // In progress installs.
   std::set<GURL> installs_;
 
   // Used to get |weak_ptr_|.
   base::WeakPtrFactory<WebApkInstallService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebApkInstallService);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INSTALL_SERVICE_H_