Add invalidation to url_response_disk_cache.

Add invalidation to url_response_disk_cache.

Entry in the disk cache are invalidated when requested offline. They can
be revalidated by caching a new version or explicitely revalidating the
entry.

This is necessary because if a downloaded application is buggy and crash
the shell, it will never be updated and the user would be stuck in a
crashing state. With this change, the crash will prevent the
revalidation of the entry, and the next run will force an update of the
application.

R=etiennej@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/8dbcae1ef2202ffe7d8939d976ab1766112972d9

[etiennej, 2015-09-22 14:53:29]

lgtm

https://codereview.chromium.org/1351693007/diff/1/shell/application_manager/n...
File shell/application_manager/network_fetcher.h (right):

https://codereview.chromium.org/1351693007/diff/1/shell/application_manager/n...
shell/application_manager/network_fetcher.h:52: void LoadFromCache();
Some documentation on these methods would be helpful in understanding what is
doing what.

[qsr, 2015-09-24 08:05:49]

Committed patchset #2 (id:20001) manually as
8dbcae1ef2202ffe7d8939d976ab1766112972d9 (presubmit successful).

[qsr, 2015-09-24 08:08:24]

https://codereview.chromium.org/1351693007/diff/1/shell/application_manager/n...
File shell/application_manager/network_fetcher.h (right):

https://codereview.chromium.org/1351693007/diff/1/shell/application_manager/n...
shell/application_manager/network_fetcher.h:52: void LoadFromCache();
On 2015/09/22 14:53:29, etiennej wrote:
> Some documentation on these methods would be helpful in understanding what is
> doing what.

Done.