Add a preference to clear plugin data on browser shutdown.

chrome/browser/plugin_data_remover_helper.cc

+// Copyright (c) 2010 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/plugin_data_remover_helper.h"
+
+#include "base/ref_counted.h"
+#include "chrome/browser/browser_thread.h"
+#include "chrome/browser/plugin_data_remover.h"
+#include "chrome/common/notification_service.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile.h"
+
+class PluginDataRemoverHelper::Internal

[Mattias Nissler (ping if slow), 2010/12/09 15:08:55]

Could use a class comment saying that it's RefCountedThreadSafe so it can
outlive the remover object?

+    : public base::RefCountedThreadSafe<PluginDataRemoverHelper::Internal> {
+ public:
+  explicit Internal(const char* pref_name, PrefService* prefs)
+      : pref_name_(pref_name), prefs_(prefs) {}
+
+  void StartUpdate() {
+    BrowserThread::PostTask(
+        BrowserThread::FILE,
+        FROM_HERE,
+        NewRunnableMethod(
+            this,
+            &PluginDataRemoverHelper::Internal::UpdateOnFileThread));
+  }
+
+  void Invalidate() {
+    prefs_ = NULL;
+  }
+
+ private:
+  friend class base::RefCountedThreadSafe<Internal>;
+
+  ~Internal() {}
+
+  void UpdateOnFileThread() {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+    bool result = PluginDataRemover::IsSupported();
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        NewRunnableMethod(this,
+                          &PluginDataRemoverHelper::Internal::SetPrefOnUIThread,
+                          result));
+  }
+
+  void SetPrefOnUIThread(bool value) {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    if (prefs_)
+      prefs_->SetBoolean(pref_name_.c_str(), value);
+  }
+
+  std::string pref_name_;
+  // Weak pointer.
+  PrefService* prefs_;
+
+  DISALLOW_COPY_AND_ASSIGN(Internal);
+};
+
+PluginDataRemoverHelper::PluginDataRemoverHelper() {}
+
+PluginDataRemoverHelper::~PluginDataRemoverHelper() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (internal_)
+    internal_->Invalidate();
+}
+
+void PluginDataRemoverHelper::Init(const char* pref_name,
+                                   PrefService* prefs,
+                                   NotificationObserver* observer) {
+  pref_.Init(pref_name, prefs, observer);
+  registrar_.Add(this, NotificationType::PLUGIN_ENABLE_STATUS_CHANGED,
+                 NotificationService::AllSources());
+  internal_ = make_scoped_refptr(new Internal(pref_name, prefs));
+  internal_->StartUpdate();
+}
+
+void PluginDataRemoverHelper::Observe(NotificationType type,
+                                      const NotificationSource& source,
+                                      const NotificationDetails& details) {
+  if (type.value == NotificationType::PLUGIN_ENABLE_STATUS_CHANGED) {
+    internal_->StartUpdate();
+  } else {
+    NOTREACHED();
+  }
+}