Implement server-suggested update check backoff

chrome/browser/android/webapk/webapk_installer.cc

Index: chrome/browser/android/webapk/webapk_installer.cc
diff --git a/chrome/browser/android/webapk/webapk_installer.cc b/chrome/browser/android/webapk/webapk_installer.cc
index 2d17c84918a80ebbe6e541a35974d4458cc193b5..8bab7e2afcef0ec02843b7e507786f4045e02305 100644
--- a/chrome/browser/android/webapk/webapk_installer.cc
+++ b/chrome/browser/android/webapk/webapk_installer.cc
@@ -352,6 +352,7 @@ WebApkInstaller::WebApkInstaller(content::BrowserContext* browser_context,
       server_url_(GetServerUrl()),
       webapk_download_url_timeout_ms_(kWebApkDownloadUrlTimeoutMs),
       download_timeout_ms_(kDownloadTimeoutMs),
+      less_updates_(false),
       task_type_(UNDEFINED),
       weak_ptr_factory_(this) {
   CreateJavaRef();
@@ -416,9 +417,10 @@ void WebApkInstaller::OnURLFetchComplete(const net::URLFetcher* source) {
   }
 
   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()) {
+    less_updates_ = response->infrequent_updates();

[pkotwicz, 2017/02/14 00:15:13]

Nit: Rename the field in the proto to |less_updates|

[dominickn, 2017/02/14 04:13:34]

I'd call it relax_updates

[Xi Han, 2017/02/14 22:25:47]

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;
   }
@@ -625,11 +627,11 @@ void WebApkInstaller::OnTimeout() {
 }
 
 void WebApkInstaller::OnSuccess() {
-  finish_callback_.Run(true, webapk_package_);
+  finish_callback_.Run(true, webapk_package_, less_updates_);
   delete this;
 }
 
 void WebApkInstaller::OnFailure() {
-  finish_callback_.Run(false, webapk_package_);
+  finish_callback_.Run(false, webapk_package_, less_updates_);
   delete this;
 }