Store URLs in WebappDataStorage, and purge them when history is cleared.

chrome/browser/browsing_data/browsing_data_remover.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/browsing_data/browsing_data_remover.h"
 
 #include <map>
 #include <set>
 #include <string>
 
@@ skipping 538 matching lines @@
     if (!precache_manager) {
       waiting_for_clear_precache_history_ = true;
       precache_manager->ClearHistory();
       // The above calls are done on the UI thread but do their work on the DB
       // thread. So wait for it.
       BrowserThread::PostTaskAndReply(
           BrowserThread::DB, FROM_HERE, base::Bind(&base::DoNothing),
           base::Bind(&BrowsingDataRemover::OnClearedPrecacheHistory,
                      weak_ptr_factory_.GetWeakPtr()));
     }
+
+    // Clear the history information (last launch time and origin URL) of any
+    // registered webapps.
+    waiting_for_clear_webapp_history_ = true;

[gone, 2016/03/08 22:40:39]

The other clearing functions generally seem to PostTaskAndReply; is that not
required in this case because of the AsyncTask in Java land?  If so, it'd be
worth commenting on that here.

[dominickn, 2016/03/09 08:18:33]

I actually have no idea, I was just doing this the same way that the other JNI
call does it. :)

[gone, 2016/03/10 23:27:21]

Ah, in that case could you leave a comment to make it clearer?

[dominickn, 2016/03/11 05:14:42]

Done. The threading model across JNI calls is still evil black magic to me.

+    WebappRegistry::ClearWebappHistory(
+        base::Bind(&BrowsingDataRemover::OnClearedWebappHistory,
+          weak_ptr_factory_.GetWeakPtr()));
 #endif
 
     data_reduction_proxy::DataReductionProxySettings*
         data_reduction_proxy_settings =
             DataReductionProxyChromeSettingsFactory::GetForBrowserContext(
                 profile_);
     // |data_reduction_proxy_settings| is null if |profile_| is off the record.
     if (data_reduction_proxy_settings) {
       data_reduction_proxy::DataReductionProxyService*
           data_reduction_proxy_service =
@@ skipping 430 matching lines @@
          !waiting_for_clear_network_predictor_ &&
          !waiting_for_clear_networking_history_ &&
          !waiting_for_clear_passwords_ &&
          !waiting_for_clear_passwords_stats_ &&
          !waiting_for_clear_platform_keys_ &&
          !waiting_for_clear_plugin_data_ &&
          !waiting_for_clear_pnacl_cache_ &&
 #if BUILDFLAG(ANDROID_JAVA_UI)
          !waiting_for_clear_precache_history_ &&
          !waiting_for_clear_webapp_data_ &&
+         !waiting_for_clear_webapp_history_ &&
          !waiting_for_clear_offline_page_data_ &&
 #endif
 #if defined(ENABLE_WEBRTC)
          !waiting_for_clear_webrtc_logs_ &&
 #endif
          !waiting_for_clear_storage_partition_data_;
 }
 
 void BrowsingDataRemover::OnKeywordsLoaded() {
   // Deletes the entries from the model, and if we're not waiting on anything
@@ skipping 172 matching lines @@
   waiting_for_clear_precache_history_ = false;
   NotifyIfDone();
 }
 
 void BrowsingDataRemover::OnClearedWebappData() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   waiting_for_clear_webapp_data_ = false;
   NotifyIfDone();
 }
 
+void BrowsingDataRemover::OnClearedWebappHistory() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  waiting_for_clear_webapp_history_ = false;
+  NotifyIfDone();
+}
+
 void BrowsingDataRemover::OnClearedOfflinePageData() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   waiting_for_clear_offline_page_data_ = false;
   NotifyIfDone();
 }
 #endif
 
 void BrowsingDataRemover::OnClearedDomainReliabilityMonitor() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   waiting_for_clear_domain_reliability_monitor_ = false;
   NotifyIfDone();
 }
 
 // static
 BrowsingDataRemover::CallbackSubscription
     BrowsingDataRemover::RegisterOnBrowsingDataRemovedCallback(
         const BrowsingDataRemover::Callback& callback) {
   return GetOnBrowsingDataRemovedCallbacks()->Add(callback);
 }