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

0 files changed, 0 insertions, 0 deletions