Implement server-suggested update check backoff

chrome/browser/android/webapk/webapk_installer.h

Index: chrome/browser/android/webapk/webapk_installer.h
diff --git a/chrome/browser/android/webapk/webapk_installer.h b/chrome/browser/android/webapk/webapk_installer.h
index 94b807c84969a34cb7da29275da9b040c4b437b6..36c23a0a8cb7d508ac093d553678fb88b5f26742 100644
--- a/chrome/browser/android/webapk/webapk_installer.h
+++ b/chrome/browser/android/webapk/webapk_installer.h
@@ -39,11 +39,22 @@ class WebApkIconHasher;
 // Java WebApkInstaller counterpart.
 class WebApkInstaller : public net::URLFetcherDelegate {
  public:
+  // This struct is passed to an FinishCallback when a WebAPK install or update
+  // is finished. TODO.
+  struct FinishCallbackData {

[pkotwicz, 2017/02/10 02:51:22]

Can we change FinishCallback to have three arguments instead of introducing this
struct?

[Xi Han, 2017/02/13 22:56:15]

Done.

+    // The package name of the WebAPK installed or updated.
+    const std::string& webapk_package_name;
+
+    // True if Chrome received a "don't update so frequently" directive from the
+    // WebAPK server.
+    const bool infrequent_updates;
+  };
+
   // Called when the creation/updating of a WebAPK is finished or failed.
   // Parameters:
   // - whether the process succeeds.
   // - the package name of the WebAPK.
-  using FinishCallback = base::Callback<void(bool, const std::string&)>;
+  using FinishCallback = base::Callback<void(bool, const FinishCallbackData&)>;
 
   ~WebApkInstaller() override;
 
@@ -270,6 +281,9 @@ class WebApkInstaller : public net::URLFetcherDelegate {
   // WebAPK package name.
   std::string webapk_package_;
 
+  // Whether to update an WebAPK less frequently.

[pkotwicz, 2017/02/10 02:51:22]

How about: "Whether the server wants the WebAPK to request updates less
frequently."

How about renaming |infrequent_updates_| to |less_updates_|
I prefer "less" than "infrequent" because "less" is a command. "Less" is what
the server is requesting from the client.

[Xi Han, 2017/02/13 22:56:14]

Done.

+  bool infrequent_updates_;
+
   // WebAPK version code.
   int webapk_version_;