Changing tab closure handling logic in speech recognition code and cleaning bubble controller. (Spe…

chrome/browser/speech/tab_watcher.h

+// 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.
+
+#ifndef CHROME_BROWSER_SPEECH_TAB_WATCHER_H_
+#define CHROME_BROWSER_SPEECH_TAB_WATCHER_H_
+#pragma once
+
+#include <set>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_observer.h"
+
+namespace content {
+class NotificationRegistrar;
+class WebContents;
+}
+
+// Simple utility to get notified when a WebContent (a tab or an extension's
+// background page) is closed or crashes. Both the callback site and the
+// callback thread are passed by the caller in the constructor.
+// There is no restriction on the constructor, however this class must be
+// destroyed on the UI thread, due to the NotificationRegistrar dependency.
+class TabWatcher
+    : public base::RefCountedThreadSafe<TabWatcher>,
+      public content::NotificationObserver {
+ public:
+  typedef base::Callback<void(int render_process_id, int render_view_id)>
+      TabClosedCallback;
+
+  TabWatcher(TabClosedCallback tab_closed_callback,
+             content::BrowserThread::ID callback_thread);
+
+  // Starts monitoring the WebContents corresponding to the given
+  // |render_process_id|, |render_view_id| pair, invoking |tab_closed_callback_|
+  // if closed/unloaded.
+  void Watch(int render_process_id, int render_view_id);
+
+ private:
+  friend class base::RefCountedThreadSafe<TabWatcher>;
+
+  virtual ~TabWatcher();
+
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  // Lazy-initialized and used on the UI thread to handle web contents
+  // notifications (tab closing).
+  scoped_ptr<content::NotificationRegistrar> registrar_;
+
+  // Keeps track of which WebContent(s) have been registered, in order to avoid
+  // double registrations on |registrar_|
+  std::set<content::WebContents*> registered_web_contents_;
+
+  // Callback used to notify, on the thread specified by |callback_thread_| the
+  // closure of a registered tab.
+  TabClosedCallback tab_closed_callback_;
+  content::BrowserThread::ID callback_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(TabWatcher);
+};
+
+#endif  // CHROME_BROWSER_SPEECH_TAB_WATCHER_H_