Implement server-suggested update check backoff

chrome/browser/android/webapk/webapk_installer_unittest.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/android/webapk/webapk_installer.h"
 
 #include <jni.h>
 #include <memory>
 #include <string>
 
@@ skipping 145 matching lines @@
 
   void Run() {
     base::RunLoop run_loop;
     on_completed_callback_ = run_loop.QuitClosure();
     run_loop.Run();
   }
 
   bool success() { return success_; }
 
  private:
-  void OnCompleted(bool success, const std::string& webapk_package) {
+  void OnCompleted(bool success,
+                   const std::string& webapk_package,
+                   bool less_updates) {
     success_ = success;
     on_completed_callback_.Run();
   }
 
   content::BrowserContext* browser_context_;
 
   // The Web Manifest's icon URL.
   const GURL best_primary_icon_url_;
 
   // Called after the installation process has succeeded or failed.
@@ skipping 331 matching lines @@
     icons[i] = manifest.icons(i);
 
   EXPECT_EQ(best_primary_icon_url.spec(), icons[0].src());
   EXPECT_EQ(best_primary_icon_murmur2_hash, icons[0].hash());
   EXPECT_TRUE(icons[0].has_image_data());
 
   EXPECT_EQ(icon_url_1.spec(), icons[1].src());
   EXPECT_EQ(icon_murmur2_hash_1, icons[1].hash());
   EXPECT_FALSE(icons[1].has_image_data());
 }