Introduce browser_sync::ExtensionsActivityMonitor to collect extensions API u...

chrome/browser/sync/util/extensions_activity_monitor.cc

+// Copyright (c) 2009 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/sync/util/extensions_activity_monitor.h"
+
+#include "base/task.h"
+#include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/extensions/extension_bookmarks_module.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/notification_service.h"
+
+namespace browser_sync {
+
+namespace {
+// A helper task to register an ExtensionsActivityMonitor as an observer of
+// events on the UI thread (even though the monitor may live on another thread).
+// This liberates ExtensionsActivityMonitor from having to be ref counted.
+class RegistrationTask : public Task {
+ public:
+  RegistrationTask(ExtensionsActivityMonitor* monitor,
+                   MessageLoop* ui_loop,
+                   NotificationRegistrar* registrar)
+      : monitor_(monitor), ui_loop_(ui_loop), registrar_(registrar) {}
+  virtual ~RegistrationTask() {}
+
+  virtual void Run() {
+    DCHECK_EQ(MessageLoop::current(),
+              ChromeThread::GetMessageLoop(ChromeThread::UI));
+
+    // It would be nice if we could specify a Source for each specific function
+    // we wanted to observe, but the actual function objects are allocated on
+    // the fly so there is no reliable object to point to (same problem if we
+    // wanted to use the string name).  Thus, we use all sources and filter in
+    // Observe.
+    registrar_->Add(monitor_, NotificationType::EXTENSION_BOOKMARKS_API_INVOKED,
+                    NotificationService::AllSources());
+  }
+
+ private:
+  ExtensionsActivityMonitor* monitor_;
+  MessageLoop* const ui_loop_;
+  NotificationRegistrar* registrar_;
+  DISALLOW_COPY_AND_ASSIGN(RegistrationTask);
+};
+}  // namespace
+
+ExtensionsActivityMonitor::ExtensionsActivityMonitor(MessageLoop* ui_loop)
+    : ui_loop_(ui_loop) {
+  ui_loop_->PostTask(FROM_HERE, new RegistrationTask(this, ui_loop,
+                                                     &registrar_));
+}
+
+ExtensionsActivityMonitor::~ExtensionsActivityMonitor() {
+  DCHECK_EQ(MessageLoop::current(), ui_loop_);
+  // The registrar calls RemoveAll in its dtor (which would happen in a moment)
+  // but explicitly call this so it is clear why we need to be on the ui_loop_.
+  registrar_.RemoveAll();
+}
+
+void ExtensionsActivityMonitor::GetAndClearRecords(Records* buffer) {
+  AutoLock lock(records_lock_);
+  buffer->clear();
+  buffer->swap(records_);
+}
+
+void ExtensionsActivityMonitor::PutRecords(const Records& records) {
+  AutoLock lock(records_lock_);
+  for (Records::const_iterator i = records.begin(); i != records.end(); ++i) {
+    records_[i->first].extension_id = i->second.extension_id;
+    records_[i->first].bookmark_write_count += i->second.bookmark_write_count;
+  }
+}
+
+void ExtensionsActivityMonitor::Observe(NotificationType type,
+                                        const NotificationSource& source,
+                                        const NotificationDetails& details) {
+  AutoLock lock(records_lock_);
+  DCHECK_EQ(MessageLoop::current(), ui_loop_);
+  const Extension* extension = Source<const Extension>(source).ptr();
+  const BookmarksFunction* f = Details<const BookmarksFunction>(details).ptr();
+  if (f->name() == "bookmarks.update" ||
+      f->name() == "bookmarks.move" ||
+      f->name() == "bookmarks.create" ||
+      f->name() == "bookmarks.removeTree" ||
+      f->name() == "bookmarks.remove") {
+    Record& record = records_[extension->id()];
+    record.extension_id = extension->id();
+    record.bookmark_write_count++;
+  }
+}
+
+}  // namespace browser_sync