Persist sessionStorage on disk.

chrome/browser/ui/startup/session_crashed_prompt.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/startup/session_crashed_prompt.h"
 
 #include "chrome/browser/infobars/infobar_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_restore.h"
 #include "chrome/browser/tab_contents/confirm_infobar_delegate.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
+#include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/url_constants.h"
+#include "content/public/browser/dom_storage_context.h"
+#include "content/public/browser/notification_service.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "grit/theme_resources_standard.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace {
 
 // A delegate for the InfoBar shown when the previous session has crashed.
-class SessionCrashedInfoBarDelegate : public ConfirmInfoBarDelegate {
+class SessionCrashedInfoBarDelegate : public ConfirmInfoBarDelegate,
+                                      public content::NotificationObserver {
  public:
   explicit SessionCrashedInfoBarDelegate(InfoBarTabHelper* infobar_helper);
 
  private:
   virtual ~SessionCrashedInfoBarDelegate();
 
   // ConfirmInfoBarDelegate:
   virtual gfx::Image* GetIcon() const OVERRIDE;
   virtual string16 GetMessageText() const OVERRIDE;
   virtual int GetButtons() const OVERRIDE;
   virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
 
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  content::NotificationRegistrar registrar_;
+  bool accepted_;
+  Browser* browser_;
+
   DISALLOW_COPY_AND_ASSIGN(SessionCrashedInfoBarDelegate);
 };
 
 SessionCrashedInfoBarDelegate::SessionCrashedInfoBarDelegate(
     InfoBarTabHelper* infobar_helper)
-    : ConfirmInfoBarDelegate(infobar_helper) {
+    : ConfirmInfoBarDelegate(infobar_helper),
+      accepted_(false),
+      browser_(browser::FindBrowserWithWebContents(owner()->web_contents())) {
+  registrar_.Add(this, chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED,
+                 content::NotificationService::AllSources());
 }
 
 SessionCrashedInfoBarDelegate::~SessionCrashedInfoBarDelegate() {
 }
 
 gfx::Image* SessionCrashedInfoBarDelegate::GetIcon() const {
   return &ResourceBundle::GetSharedInstance().GetNativeImageNamed(
       IDR_INFOBAR_RESTORE_SESSION);
 }
 
 string16 SessionCrashedInfoBarDelegate::GetMessageText() const {
   return l10n_util::GetStringUTF16(IDS_SESSION_CRASHED_VIEW_MESSAGE);
 }
 
 int SessionCrashedInfoBarDelegate::GetButtons() const {
   return BUTTON_OK;
 }
 
 string16 SessionCrashedInfoBarDelegate::GetButtonLabel(
     InfoBarButton button) const {
   DCHECK_EQ(BUTTON_OK, button);
   return l10n_util::GetStringUTF16(IDS_SESSION_CRASHED_VIEW_RESTORE_BUTTON);
 }
 
 bool SessionCrashedInfoBarDelegate::Accept() {
   uint32 behavior = 0;
-  Browser* browser =
-      browser::FindBrowserWithWebContents(owner()->web_contents());
-  if (browser->tab_count() == 1 &&
-      chrome::GetWebContentsAt(browser, 0)->GetURL() ==
+  if (browser_->tab_count() == 1 &&
+      chrome::GetWebContentsAt(browser_, 0)->GetURL() ==
           GURL(chrome::kChromeUINewTabURL)) {
     // There is only one tab and its the new tab page, make session restore
     // clobber it.
     behavior = SessionRestore::CLOBBER_CURRENT_TAB;
   }
   SessionRestore::RestoreSession(
-      browser->profile(), browser, behavior, std::vector<GURL>());
+      browser_->profile(), browser_, behavior, std::vector<GURL>());
+  accepted_ = true;
   return true;
 }
 
+void SessionCrashedInfoBarDelegate::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {

[Peter Kasting, 2012/07/16 17:41:02]

Nit: Do a DCHECK_EQ(chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED, type);
instead of this switch

[marja, 2012/08/06 11:53:33]

Done.

+    case chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED:
+      // If the info bar wasn't accepted, it was either dismissed or expired. In
+      // that case, session restore won't happen.
+      if (!accepted_) {

[Peter Kasting, 2012/07/16 17:41:02]

You're running this code when any infobar is closed.  You need to check that the
notification is for the infobar you care about.

Also, since you're adding this observer in the delegate itself, you need to
handle both the case where you get this notification and the case where you're
destroyed before you get it, since either one might happen.  Also add a TODO
comment that you can safely eliminate the listener and rely on reaching your
destructor once InfoBars own their delegates.

[marja, 2012/08/06 11:53:33]

Ahh, thanks for pointing that out.

Done.

+        content::DOMStorageContext* dom_storage_context =
+            content::BrowserContext::GetDOMStorageContext(browser_->profile());
+        dom_storage_context->StartScavengingUnusedSessionStorage();
+      }
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
 }  // namespace
 
 namespace chrome {
 
 void ShowSessionCrashedPrompt(Browser* browser) {
   // Assume that if the user is launching incognito they were previously
   // running incognito so that we have nothing to restore from.
   if (browser->profile()->IsOffTheRecord())
     return;
 
   // In ChromeBot tests, there might be a race. This line appears to get
   // called during shutdown and |tab| can be NULL.
   TabContents* tab = chrome::GetActiveTabContents(browser);
   if (!tab)
     return;
 
   // Don't show the info-bar if there are already info-bars showing.
   if (tab->infobar_tab_helper()->infobar_count() > 0)
     return;
 
   tab->infobar_tab_helper()->AddInfoBar(
       new SessionCrashedInfoBarDelegate(tab->infobar_tab_helper()));
 }
 
 }  // namespace chrome