Hey +dknox - I'm guessing that when I blacklist the dialog, this should NOT cause other important site functionality to stop. As in, if the dialog is blacklisted, then the 'Manage Storage' UI should still be able to 'clear all but important', correct?

That sounds right to me

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33

commit 93fa43b36cf37af0b142fbe70d7e1cc3f05bca33
Author: dmurph <dmurph@chromium.org>
Date: Tue Feb 07 23:45:16 2017

[ImportantSites] Implementing dialog level blacklisting and blacklist expiration

R=dominickn,twellington
BUG= 682015 , 682016 

Review-Url: https://codereview.chromium.org/2669873002
Cr-Commit-Position: refs/heads/master@{#448795}

[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/android/java/src/org/chromium/chrome/browser/preferences/PrefServiceBridge.java
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/browser/android/preferences/pref_service_bridge.cc
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/browser/engagement/important_sites_util.cc
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/browser/engagement/important_sites_util.h
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/browser/engagement/important_sites_util_unittest.cc
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/browser/prefs/browser_prefs.cc
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/common/pref_names.cc
[modify] https://crrev.com/93fa43b36cf37af0b142fbe70d7e1cc3f05bca33/chrome/common/pref_names.h