Added completion notification to Profile's ClearNetworkingHistorySince.

chrome/browser/net/http_server_properties_manager.cc

Index: chrome/browser/net/http_server_properties_manager.cc
diff --git a/chrome/browser/net/http_server_properties_manager.cc b/chrome/browser/net/http_server_properties_manager.cc
index 02a173fab5ab6869ec21a7ab2285af792beaa6aa..461a1d9e4a03ff183b20b5e513654b8f22051e47 100644
--- a/chrome/browser/net/http_server_properties_manager.cc
+++ b/chrome/browser/net/http_server_properties_manager.cc
@@ -91,11 +91,16 @@ void HttpServerPropertiesManager::RegisterPrefs(PrefService* prefs) {
                                 PrefService::UNSYNCABLE_PREF);
 }
 
+// This is required for conformance with the HttpServerProperties interface.
 void HttpServerPropertiesManager::Clear() {
+  Clear(base::Closure());
+}
+
+void HttpServerPropertiesManager::Clear(const base::Closure& completion) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   http_server_properties_impl_->Clear();
-  ScheduleUpdatePrefsOnIO();
+  UpdatePrefsFromCacheOnIO(completion);
 }
 
 bool HttpServerPropertiesManager::SupportsSpdy(
@@ -441,7 +446,13 @@ void HttpServerPropertiesManager::StartPrefsUpdateTimerOnIO(
       &HttpServerPropertiesManager::UpdatePrefsFromCacheOnIO);
 }
 
+// This is required so we can set this as the callback for a timer.
 void HttpServerPropertiesManager::UpdatePrefsFromCacheOnIO() {
+  UpdatePrefsFromCacheOnIO(base::Closure());
+}
+
+void HttpServerPropertiesManager::UpdatePrefsFromCacheOnIO(
+    const base::Closure& completion) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   base::ListValue* spdy_server_list = new base::ListValue;
@@ -469,7 +480,8 @@ void HttpServerPropertiesManager::UpdatePrefsFromCacheOnIO() {
                  base::Owned(spdy_server_list),
                  base::Owned(spdy_settings_map),
                  base::Owned(alternate_protocol_map),
-                 base::Owned(pipeline_capability_map)));
+                 base::Owned(pipeline_capability_map),
+                 completion));
 }
 
 // A local or temporary data structure to hold |supports_spdy|, SpdySettings,
@@ -500,7 +512,8 @@ void HttpServerPropertiesManager::UpdatePrefsOnUI(
     base::ListValue* spdy_server_list,
     net::SpdySettingsMap* spdy_settings_map,
     net::AlternateProtocolMap* alternate_protocol_map,
-    net::PipelineCapabilityMap* pipeline_capability_map) {
+    net::PipelineCapabilityMap* pipeline_capability_map,
+    const base::Closure& completion) {
 
   typedef std::map<net::HostPortPair, ServerPref> ServerPrefMap;
   ServerPrefMap server_pref_map;
@@ -634,6 +647,13 @@ void HttpServerPropertiesManager::UpdatePrefsOnUI(
   pref_service_->Set(prefs::kHttpServerProperties,
                      http_server_properties_dict);
   setting_prefs_ = false;
+
+  // Note that |completion| will be fired after we have written everything to
+  // the Preferences, but likely before these changes are serialized to disk.
+  // This is not a problem though, as JSONPrefStore guarantees that this will
+  // happen, pretty soon, and even in the case we shut down immediately.
+  if (!completion.is_null())
+    completion.Run();
 }
 
 void HttpServerPropertiesManager::OnPreferenceChanged(