Whitelist the Chrome Webstore and unhide its app list item

This patch whitelists the Chrome Webstore in the SupervisedUserUrlFilter,
but only if it hasn't been specifically blocked by the parent.

Bug: 1065544
Change-Id: I7d4755e9225a83b899f73a1f0de7f1c839744097
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2133557
Auto-Submit: Dan S <danan@chromium.org>
Reviewed-by: Aga Wronska <agawronska@chromium.org>
Commit-Queue: Dan S <danan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756064}

chrome/browser/supervised_user/supervised_user_pref_store.cc

@@ -127,7 +127,7 @@ void SupervisedUserPrefStore::OnNewSettingsAvailable(
     prefs_->SetBoolean(prefs::kForceGoogleSafeSearch, true);
     prefs_->SetInteger(prefs::kForceYouTubeRestrict,
                        safe_search_util::YOUTUBE_RESTRICT_MODERATE);
-    prefs_->SetBoolean(prefs::kHideWebStoreIcon, true);
+    prefs_->SetBoolean(prefs::kHideWebStoreIcon, false);
     prefs_->SetBoolean(prefs::kSigninAllowed, false);
     prefs_->SetBoolean(feed::prefs::kEnableSnippets, false);
 

chrome/browser/supervised_user/supervised_user_url_filter.cc

@@ -391,6 +391,15 @@ SupervisedUserURLFilter::GetFilteringBehaviorForURL(
     return BLOCK;
   }
 
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+  // The user requested the Chrome Webstore, and it
+  // hasn't specifically been blocked above, so allow.
+  if (policy::url_util::Normalize(effective_url).host() ==
+      extension_urls::GetWebstoreLaunchURL().host()) {
+    return ALLOW;
+  }
+#endif
+
   // Fall back to the default behavior.
   *reason = supervised_user_error_page::DEFAULT;
   return default_behavior_;