Show offline interstitial page when offline and reload when reconnected to network.

* Added OfflineResourceHandler that intercept the request and show interstitial page.
* Added OfflineLoadPage that is shown when offline.
   This gets deleted when
    - User pressed "Load now" btton to proceed or
    - User pressed "Cancel" button to cancel loading
    - Network become available.
   The page first appears as blank page (a little darker than white for now. I'll update when mock is ready),
   and then options become available after 3 seconds maximum.
* Added unit test for OfflineLoadPage class.
* OfflineLoadService class to control when/if a load request
 should proceed regardless of network status.
 The current implementation is tentative and will proceed
 if if loading was requested in a given tab.
 I'll revisit this class to improve the logic in separate CL
 later.

Known Issue:
 - thumbnail is not working yet. I'll working on this in separate Cl.
 - a tab shows URL instead of title string. I'll fix this in separate CL.
 - InitNavigationParams in offline_load_page_unittest is copied from safe_browsing_blocking_page_unittest. I'll move this to common place in separate CL. (hopefully before checking this in)

BUG=chromium-os:3605
TEST=unit test: offline_load_page_unittest
     manual: disable wifi and ethernet, then login.
             chrome will show the offline page when tab is activated. Enable network (wifi or ethernet) and all tab will start loading again.

Review URL: http://codereview.chromium.org/2931005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@52433 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 69 insertions, 0 deletions

diff --git a/chrome/browser/chromeos/offline/offline_load_page.h b/chrome/browser/chromeos/offline/offline_load_page.h
new file mode 100644
index 0000000..3363853
--- /dev/null
+++ b/chrome/browser/chromeos/offline/offline_load_page.h
@@ -0,0 +1,69 @@
+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_OFFLINE_OFFLINE_LOAD_PAGE_H_
+#define CHROME_BROWSER_CHROMEOS_OFFLINE_OFFLINE_LOAD_PAGE_H_
+
+#include <string>
+
+#include "chrome/browser/chromeos/network_state_notifier.h"
+#include "chrome/browser/tab_contents/interstitial_page.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_service.h"
+
+class TabContents;
+
+namespace chromeos {
+
+// OfflineLoadPage class shows the interstitial page that is shown
+// when no network is available and hides when some network (either
+// one of wifi, 3g or ethernet) becomes available.
+// It deletes itself when the interstitial page is closed.
+class OfflineLoadPage : public InterstitialPage {
+ public:
+  // A delegate class that is called when the interstitinal page
+  // is closed.
+  class Delegate {
+   public:
+    Delegate() {}
+    virtual ~Delegate() {}
+    // Called when a user selected to proceed or not to proceed
+    // with loading.
+    virtual void OnBlockingPageComplete(bool proceed) = 0;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+  static void Show(int process_host_id, int render_view_id,
+                   const GURL& url, Delegate* delegate);
+  // Import show here so that overloading works.
+  using InterstitialPage::Show;
+
+ protected:
+  // Create a offline load page for the |tab_contents|.
+  OfflineLoadPage(TabContents* tab_contents, const GURL& url,
+                  Delegate* delegate);
+  virtual ~OfflineLoadPage() {}
+
+ private:
+  // InterstitialPage implementation.
+  virtual std::string GetHTMLContents();
+  virtual void CommandReceived(const std::string& command);
+  virtual void Proceed();
+  virtual void DontProceed();
+
+  // Overrides InterstitialPage's Observe.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+  Delegate* delegate_;
+  NotificationRegistrar registrar_;
+
+  DISALLOW_COPY_AND_ASSIGN(OfflineLoadPage);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_OFFLINE_OFFLINE_LOAD_PAGE_H_