Snackbar for promoting Data Saver to existing users

chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java
index 9866be882a9f1184963f5c2582fb6c23685b9c5f..4512acf60883976f4734f6aa76544d18f9745c5d 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/datareduction/DataReductionPromoUtils.java
@@ -36,6 +36,16 @@ public class DataReductionPromoUtils {
             "displayed_data_reduction_infobar_promo_version";
 
     /**
+     * Keys used to save the content length when the snackbar promo is shown and save if the user
+     * has set the content length on the first upgrade or install to the version that shows the
+     * snackbar.

[gone, 2016/10/13 01:03:11]

Can you clean this sentence up a bit?  It's repeated throughout the file and
really, really hard to parse.  Splitting it into two would make sense since
these are javadocs, anyway.

/** Key used to save the content length when the snackbar promo was last shown.
*/

/** Key used to track whether the user has set the content length on the first
upgrade, or install of, the version that shows the snackbar. */

Also, why do you need to specify "first upgrade or install to"?  Can the user
get to the point where this boolean is recorded but not have the snackbar shown
to them?

[megjablon, 2016/10/24 23:59:00]

Done.

Yes. Added a comment. If the finch config says we are showing the snackbar for
100MB and 1GB, but the user has already saved 1GB when installing M56 then this
will initialize the starting content length to the value that the user has saved
already (which would be greater than 1GB) and they would not see the snackbars. 

+     */
+    private static final String SHARED_PREF_DISPLAYED_SNACKBAR_PROMO_CONTENT_LENGTH =
+            "displayed_data_reduction_snackbar_promo_content_length";
+    private static final String SHARED_PREF_SNACKBAR_PROMO_INIT_WITH_STARTING_CONTENT_LENGTH =
+            "data_reduction_snackbar_promo_init_with_starting_content_length";
+
+    /**
      * Returns whether any of the data reduction proxy promotions can be displayed. Checks if the
      * proxy is allowed by the DataReductionProxyConfig, already on, or if the user is managed. If
      * the data reduction proxy is managed by an administrator's policy, the user should not be
@@ -139,4 +149,50 @@ public class DataReductionPromoUtils {
         return ContextUtils.getAppSharedPreferences().getBoolean(
                 SHARED_PREF_DISPLAYED_INFOBAR_PROMO, false);
     }
+
+    /**
+     * Saves a shared pref indicating the content length when the last the snackbar promo was

[gone, 2016/10/13 01:03:11]

the last the

You might as well just flesh out the javadoc for the key itself and then leave
this as

/** See {@link #SHARED_PREF_DISPLAYED_SNACKBAR_PROMO_CONTENT_LENGTH}. */

That's let you avoid copy-pasting the same sentences everywhere.

[megjablon, 2016/10/24 23:59:00]

Done.

+     * displayed.
+     */
+    public static void saveSnackbarPromoDisplayed(long contentLength) {
+        ContextUtils.getAppSharedPreferences()
+                .edit()
+                .putLong(SHARED_PREF_DISPLAYED_SNACKBAR_PROMO_CONTENT_LENGTH, contentLength)
+                .apply();
+    }
+
+    /**
+     * Returns the content length from when the last data snackbar promo was displayed. If the promo
+     * has not been displayed before, returns -1,

[gone, 2016/10/13 01:03:11]

Maybe

/**
 * Returns the content length from when the promo snackbar was last displayed.
 *
 * @return The content length, or -1 if the promo has not been displayed before.
 */

[megjablon, 2016/10/24 23:59:00]

Done.

+     *
+     * @return The content length when the last the snackbar promo was displayed.

[gone, 2016/10/13 01:03:11]

the last the

[megjablon, 2016/10/24 23:59:00]

Done.

+     */
+    public static long getDisplayedSnackbarPromoContentLength() {
+        return ContextUtils.getAppSharedPreferences().getLong(
+                SHARED_PREF_DISPLAYED_SNACKBAR_PROMO_CONTENT_LENGTH, -1);
+    }
+
+    /**
+     * Saves a shared pref indicating the content length on the first upgrade or install to the
+     * version that shows the snackbar. Also, saves a boolean indicating that the content length has
+     * been initialized.
+     */
+    public static void saveSnackbarPromoInitWithStartingContentLength(long contentLength) {
+        ContextUtils.getAppSharedPreferences()
+                .edit()
+                .putBoolean(SHARED_PREF_SNACKBAR_PROMO_INIT_WITH_STARTING_CONTENT_LENGTH, true)
+                .putLong(SHARED_PREF_DISPLAYED_SNACKBAR_PROMO_CONTENT_LENGTH, contentLength)
+                .apply();
+    }
+
+    /**
+     * Returns a boolean indicating that the content length on the first upgrade or install to the
+     * version that shows the snackbar has been initialized.
+     *
+     * @return Whether that the starting content length has been initialized.
+     */
+    public static boolean hasSnackbarPromoBeenInitWithStartingContentLength() {
+        return ContextUtils.getAppSharedPreferences().getBoolean(
+                SHARED_PREF_SNACKBAR_PROMO_INIT_WITH_STARTING_CONTENT_LENGTH, false);
+    }
 }