Change HungPluginTabHelper to listen for infobar changes through Observer style.

chrome/browser/ui/hung_plugin_tab_helper.cc

Index: chrome/browser/ui/hung_plugin_tab_helper.cc
diff --git a/chrome/browser/ui/hung_plugin_tab_helper.cc b/chrome/browser/ui/hung_plugin_tab_helper.cc
index 374932018845c63b1e30d2a4e0e28338e40730ba..d3836d5921bc369fbff2262a63e5c945d94712b2 100644
--- a/chrome/browser/ui/hung_plugin_tab_helper.cc
+++ b/chrome/browser/ui/hung_plugin_tab_helper.cc
@@ -10,7 +10,6 @@
 #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"
@@ -18,8 +17,6 @@
 #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"
@@ -261,9 +258,8 @@ HungPluginTabHelper::PluginState::~PluginState() {
 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() {
@@ -279,6 +275,11 @@ void HungPluginTabHelper::PluginCrashed(const base::FilePath& plugin_path,
   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();
@@ -301,6 +302,11 @@ void HungPluginTabHelper::PluginHungStatusChanged(
   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) {
@@ -321,33 +327,6 @@ void HungPluginTabHelper::PluginHungStatusChanged(
   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
@@ -422,3 +401,37 @@ void HungPluginTabHelper::CloseBar(PluginState* state) {
     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);
+}