Implement server-suggested update check backoff

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
index d6057db320ecb29b52725d6b63716bbf803bc6c6..fa674a810a39167c18e453e02b774700067faa49 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
@@ -58,6 +58,9 @@ public class WebappDataStorage {
     static final String KEY_DID_LAST_WEBAPK_UPDATE_REQUEST_SUCCEED =
             "did_last_webapk_update_request_succeed";
 
+    // Whether to check updates less frequently.
+    static final String KEY_INFREQUENT_UPDATES = "infrequent_updates";
+
     // Unset/invalid constants for last used times and URLs. 0 is used as the null last used time as
     // WebappRegistry assumes that this is always a valid timestamp.
     static final long LAST_USED_UNSET = 0;
@@ -301,6 +304,7 @@ public class WebappDataStorage {
         editor.remove(KEY_LAST_CHECK_WEB_MANIFEST_UPDATE_TIME);
         editor.remove(KEY_LAST_WEBAPK_UPDATE_REQUEST_COMPLETE_TIME);
         editor.remove(KEY_DID_LAST_WEBAPK_UPDATE_REQUEST_SUCCEED);
+        editor.remove(KEY_INFREQUENT_UPDATES);
         editor.apply();
     }
 
@@ -401,6 +405,20 @@ public class WebappDataStorage {
         return mPreferences.getBoolean(KEY_DID_LAST_WEBAPK_UPDATE_REQUEST_SUCCEED, false);
     }
 
+    /**
+     * Updates the result of whether to check updates less frequently.

[pkotwicz, 2017/02/10 20:53:14]

Nit: "Updates the result of whether" -> "Updates whether"

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

Done.

+     */
+    void updateInfrequentUpdates(boolean isInfrequentUpdates) {
+        mPreferences.edit().putBoolean(KEY_INFREQUENT_UPDATES, isInfrequentUpdates).apply();
+    }
+
+    /**
+     * Returns whether to check updates less frequently.
+     */
+    boolean getInfrequentUpdates() {
+        return mPreferences.getBoolean(KEY_INFREQUENT_UPDATES, false);
+    }
+
     protected WebappDataStorage(String webappId) {
         mId = webappId;
         mPreferences = ContextUtils.getApplicationContext().getSharedPreferences(