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),
+      observer_installed_(false) {
 }
 
 HungPluginTabHelper::~HungPluginTabHelper() {
 }
 
 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)
     return;
 
+  if (!observer_installed_) {
+    observer_installed_ = true;
+    infobar_service->AddObserver(this);

[Peter Kasting, 2014/05/30 18:05:48]

Why do we want to add an observer here?  We don't seem to be adding any
infobars.

+  }
+
   // For now, just do a brute-force search to see if we have this plugin. Since
   // we'll normally have 0 or 1, this is fast.
   for (PluginStateMap::iterator i = hung_plugins_.begin();
        i != hung_plugins_.end(); ++i) {
     if (i->second->path == plugin_path) {
       if (i->second->infobar)
         infobar_service->RemoveInfoBar(i->second->infobar);
       hung_plugins_.erase(i);
       break;
     }
   }
 }
 
 void HungPluginTabHelper::PluginHungStatusChanged(
     int plugin_child_id,
     const base::FilePath& plugin_path,
     bool is_hung) {
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents());
   if (!infobar_service)
     return;
 
+  if (!observer_installed_) {
+    observer_installed_ = true;
+    infobar_service->AddObserver(this);

[Peter Kasting, 2014/05/30 18:05:48]

Wouldn't we want this in ShowBar() instead of here?  Otherwise, can't
OnReshowTimer() add a bar that we don't observe?

Also, where is the balancing RemoveObserver() call to this?  We only seem to
have one if the manager is shutting down.

+  }
+
   PluginStateMap::iterator found = hung_plugins_.find(plugin_child_id);
   if (found != hung_plugins_.end()) {
     if (!is_hung) {
       // Hung plugin became un-hung, close the infobar and delete our info.
       if (found->second->infobar)
         infobar_service->RemoveInfoBar(found->second->infobar);
       hung_plugins_.erase(found);
     }
     return;
   }
 
   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;
-  for (PluginStateMap::iterator i = hung_plugins_.begin();
-       i != hung_plugins_.end(); ++i) {
-    PluginState* state = i->second.get();
-    if (state->infobar == infobar) {
-      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.
-      state->next_reshow_delay *= 2;
-      return;
-    }
-  }
-}
-
 void HungPluginTabHelper::KillPlugin(int child_id) {
 #if defined(OS_WIN)
   // Dump renderers that are sending or receiving pepper messages, in order to
   // diagnose inter-process deadlocks.
   // Only do that on the Canary channel, for 20% of pepper plugin hangs.
   if (base::RandInt(0, 100) < 20) {
     chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
     if (channel == chrome::VersionInfo::CHANNEL_CANARY) {
       scoped_ptr<OwnedHandleVector> renderer_handles(new OwnedHandleVector);
       HANDLE current_process = ::GetCurrentProcess();
@@ skipping 54 matching lines @@
 }
 
 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;
   }
 }
+
+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) {
+      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.
+      state->next_reshow_delay *= 2;
+      return;
+    }
+  }
+}
+
+void HungPluginTabHelper::OnManagerShuttingDown(
+    infobars::InfoBarManager* manager) {
+  InfoBarService* infobar_service =
+      InfoBarService::FromWebContents(web_contents());
+  if (!infobar_service)
+    return;
+
+  if (observer_installed_)
+    infobar_service->RemoveObserver(this);
+}