Implement server-suggested update check backoff

chrome/browser/android/webapk/webapk_installer.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 "base/android/build_info.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/path_utils.h"
@@ skipping 335 matching lines @@
 WebApkInstaller::WebApkInstaller(content::BrowserContext* browser_context,
                                  const ShortcutInfo& shortcut_info,
                                  const SkBitmap& shortcut_icon)
     : request_context_getter_(
           Profile::FromBrowserContext(browser_context)->GetRequestContext()),
       shortcut_info_(shortcut_info),
       shortcut_icon_(shortcut_icon),
       server_url_(GetServerUrl()),
       webapk_download_url_timeout_ms_(kWebApkDownloadUrlTimeoutMs),
       download_timeout_ms_(kDownloadTimeoutMs),
+      relax_updates_(false),

[pkotwicz, 2017/03/04 00:20:47]

Nit: Can you initialize |webapk_version_| ?

[Xi Han, 2017/03/06 22:14:21]

Done.

       task_type_(UNDEFINED),
       weak_ptr_factory_(this) {
   CreateJavaRef();
 }
 
 void WebApkInstaller::CreateJavaRef() {
   JNIEnv* env = base::android::AttachCurrentThread();
   java_ref_.Reset(
       Java_WebApkInstaller_create(env, reinterpret_cast<intptr_t>(this)));
 }
@@ skipping 47 matching lines @@
   source->GetResponseAsString(&response_string);
 
   std::unique_ptr<webapk::WebApkResponse> response(new webapk::WebApkResponse);
   if (!response->ParseFromString(response_string)) {
     LOG(WARNING) << "WebAPK server did not return proto.";
     OnFailure();
     return;
   }
 
   GURL signed_download_url(response->signed_download_url());
-  // https://crbug.com/680131. The server sends an empty URL if the server does
-  // not have a newer WebAPK to update to.
   if (task_type_ == UPDATE && signed_download_url.is_empty()) {
+    relax_updates_ = response->relax_updates();

[pkotwicz, 2017/03/04 00:20:47]

Nit: Move the setting of |relax_updates_| after the comment

[Xi Han, 2017/03/06 22:14:21]

Done.

+    // https://crbug.com/680131. The server sends an empty URL if the server
+    // does not have a newer WebAPK to update to.
     OnSuccess();
     return;
   }
 
   if (!signed_download_url.is_valid() || response->package_name().empty()) {
     LOG(WARNING) << "WebAPK server returned incomplete proto.";
     OnFailure();
     return;
   }
 
@@ skipping 184 matching lines @@
   }
   if (!success)
     OnFailure();
 }
 
 void WebApkInstaller::OnTimeout() {
   OnFailure();
 }
 
 void WebApkInstaller::OnSuccess() {
-  finish_callback_.Run(true, webapk_package_);
+  finish_callback_.Run(true, relax_updates_, webapk_package_);
   delete this;
 }
 
 void WebApkInstaller::OnFailure() {
-  finish_callback_.Run(false, webapk_package_);
+  finish_callback_.Run(false, relax_updates_, webapk_package_);
   delete this;
 }