Extension activity log database refactoring (step 1)

chrome/browser/extensions/activity_log/activity_log.cc

 // Copyright (c) 2011 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 <set>
 #include <vector>
 #include "base/command_line.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
@@ skipping 114 matching lines @@
 }
 
 ActivityLogFactory::~ActivityLogFactory() {
 }
 
 // ActivityLog
 
 void ActivityLog::SetDefaultPolicy(ActivityLogPolicy::PolicyType policy_type) {
   // Can't use IsLogEnabled() here because this is called from inside Init.
   if (policy_type != policy_type_ && enabled_) {
-    delete policy_;
+    // Deleting the old policy takes place asynchronously, on the database
+    // thread.  Initializing a new policy below similarly happens
+    // asynchronously.  Since the two operations are both queued for the
+    // database, the queue ordering should ensure that the deletion completes
+    // before database initialization occurs.
+    //
+    // However, changing policies at runtime is still not recommended, and
+    // likely only should be done for unit tests.
+    if (policy_)
+      policy_->Close();
+
     switch (policy_type) {
       case ActivityLogPolicy::POLICY_FULLSTREAM:
         policy_ = new FullStreamUIPolicy(profile_);
         break;
       case ActivityLogPolicy::POLICY_NOARGS:
         policy_ = new StreamWithoutArgsUIPolicy(profile_);
         break;
       default:
         NOTREACHED();
     }
@@ skipping 54 matching lines @@
     SetDefaultPolicy(ActivityLogPolicy::POLICY_FULLSTREAM);
   else
     SetDefaultPolicy(ActivityLogPolicy::POLICY_NOARGS);
 }
 
 void ActivityLog::Shutdown() {
   if (tracker_) tracker_->RemoveObserver(this);
 }
 
 ActivityLog::~ActivityLog() {
-  // TODO(felt): Turn policy_ into a scoped_ptr.
-  delete policy_;
+  if (policy_)
+    policy_->Close();
 }
 
 bool ActivityLog::IsLogEnabled() {
   if (!has_threads_ || !initialized_) return false;
   return enabled_;
 }
 
 void ActivityLog::OnExtensionInstalled(const Extension* extension) {
   if (extension->id() != kActivityLogExtensionId) return;
   enabled_ = true;
@@ skipping 282 matching lines @@
                    web_contents->GetTitle(),
                    std::string(),  // no api call here
                    script_names.get(),
                    DomActionType::INSERTED,
                    extra);
     }
   }
 }
 
 }  // namespace extensions