Change HungPluginTabHelper to listen for infobar changes through Observer style.

chrome/browser/ui/hung_plugin_tab_helper.cc

 // 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.
 
 #include "chrome/browser/ui/hung_plugin_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process/process.h"
 #include "base/rand_util.h"
 #include "build/build_config.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/common/chrome_version_info.h"
 #include "components/infobars/core/confirm_infobar_delegate.h"
 #include "components/infobars/core/infobar.h"
 #include "content/public/browser/browser_child_process_host_iterator.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_data.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_service.h"
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/process_type.h"
 #include "content/public/common/result_codes.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/locale_settings.h"
 #include "grit/theme_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
@@ skipping 221 matching lines @@
 
 HungPluginTabHelper::PluginState::~PluginState() {
 }
 
 
 // HungPluginTabHelper --------------------------------------------------------
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(HungPluginTabHelper);
 
 HungPluginTabHelper::HungPluginTabHelper(content::WebContents* contents)
-    : content::WebContentsObserver(contents) {
-  registrar_.Add(this, chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED,
-                 content::NotificationService::AllSources());
+    : content::WebContentsObserver(contents),
+      number_of_infobars_(0) {
 }
 
 HungPluginTabHelper::~HungPluginTabHelper() {
+  // If we're getting shut down before the InfoBarService, we need to unregister
+  // as an observer.
+  if (number_of_infobars_ != 0)
+    InfoBarService::FromWebContents(web_contents())->RemoveObserver(this);
 }
 
 void HungPluginTabHelper::PluginCrashed(const base::FilePath& plugin_path,
                                         base::ProcessId plugin_pid) {
   // TODO(brettw) ideally this would take the child process ID. When we do this
   // for NaCl plugins, we'll want to know exactly which process it was since
   // the path won't be useful.
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents());
   if (!infobar_service)
@@ skipping 34 matching lines @@
 
   base::string16 plugin_name =
       content::PluginService::GetInstance()->GetPluginDisplayNameByPath(
           plugin_path);
 
   linked_ptr<PluginState> state(new PluginState(plugin_path, plugin_name));
   hung_plugins_[plugin_child_id] = state;
   ShowBar(plugin_child_id, state.get());
 }
 
-void HungPluginTabHelper::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  DCHECK_EQ(chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED, type);
-  infobars::InfoBar* infobar =
-      content::Details<infobars::InfoBar::RemovedDetails>(details)->first;
+void HungPluginTabHelper::OnInfoBarRemoved(infobars::InfoBar* infobar,
+                                           bool animate) {
   for (PluginStateMap::iterator i = hung_plugins_.begin();
        i != hung_plugins_.end(); ++i) {
     PluginState* state = i->second.get();
     if (state->infobar == infobar) {
+      --number_of_infobars_;
+      if (number_of_infobars_ == 0)
+        InfoBarService::FromWebContents(web_contents())->RemoveObserver(this);
+
       state->infobar = NULL;
 
       // Schedule the timer to re-show the infobar if the plugin continues to be
       // hung.
       state->timer.Start(FROM_HERE, state->next_reshow_delay,
           base::Bind(&HungPluginTabHelper::OnReshowTimer,
                      base::Unretained(this),
                      i->first));
 
       // Next time we do this, delay it twice as long to avoid being annoying.
@@ skipping 60 matching lines @@
 
 void HungPluginTabHelper::ShowBar(int child_id, PluginState* state) {
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents());
   if (!infobar_service)
     return;
 
   DCHECK(!state->infobar);
   state->infobar = HungPluginInfoBarDelegate::Create(infobar_service, this,
                                                      child_id, state->name);
+
+  if (state->infobar) {
+    ++number_of_infobars_;
+    if (number_of_infobars_ == 1)
+      infobar_service->AddObserver(this);
+  }
 }
 
 void HungPluginTabHelper::CloseBar(PluginState* state) {
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents());
   if (infobar_service && state->infobar) {
     infobar_service->RemoveInfoBar(state->infobar);
     state->infobar = NULL;
   }
 }