Fixes and improvements to cloud policy for extensions.

Fixes and improvements to cloud policy for extensions.

- wait for the ExtensionService to be ready before processing install
  notifications.

- avoid creating the managed storage leveldb cache if there are no policies set
  for that extension.

- filter the initial policies loaded from the component policy cache.

- always publish policy at the ForwardingPolicyProvider, even if nothing new
  was added; this sends the right notification later if a component is added
  back.

- don't trigger updates when a SchemaRegistry gets an update with an empty
  map.

- check if the Schema for an extension being shown in about:policy is valid
  before reading it.

BUG=108992
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=237111

[Joao da Silva, 2013-11-20 17:44:12]

Please review:

@Bartosz: policy/ changes

@Benjamin: extensions/ changes

@Pam: webui/ changes

Thanks!

[not at google - send to devlin, 2013-11-20 19:02:52]

lgtm

https://codereview.chromium.org/78953002/diff/1/chrome/browser/extensions/api...
File chrome/browser/extensions/api/storage/managed_value_store_cache.cc (right):

https://codereview.chromium.org/78953002/diff/1/chrome/browser/extensions/api...
chrome/browser/extensions/api/storage/managed_value_store_cache.cc:339: if
(!base::DirectoryExists(base_path_.AppendASCII(extension_id)) &&
perhaps pull this into a local method like StoreExists since it's being used
twice now.

Though I wonder if it's worthwhile pulling this into storage_factory_ proper.
Something to consider later.

[Pam (message me for reviews), 2013-11-22 13:37:07]

browser/ui/webui/policy_ui.cc LGTM

[Joao da Silva, 2013-11-25 09:12:14]

@Bartosz: ping :-)

[bartfab (slow), 2013-11-25 14:24:01]

lgtm

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
File chrome/browser/extensions/api/storage/managed_value_store_cache.cc (right):

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.cc:113: if
(!ExtensionSystem::Get(profile_)->ready().is_signaled())
Nit: #include "extensions/common/one_shot_event.h"

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.cc:339: // Don't
create the store now if there are no concrete policies configured
Nit: What do you mean by "concrete policies"? Do you mean none of the policies
are set; none of the policies have values?

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
File chrome/browser/extensions/api/storage/managed_value_store_cache.h (right):

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.h:76: bool
HasStore(const std::string& extension_id);
Nit: const

[Joao da Silva, 2013-11-25 15:40:38]

Thanks for the reviews!

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
File chrome/browser/extensions/api/storage/managed_value_store_cache.cc (right):

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.cc:113: if
(!ExtensionSystem::Get(profile_)->ready().is_signaled())
On 2013/11/25 14:24:02, bartfab wrote:
> Nit: #include "extensions/common/one_shot_event.h"

Done.

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.cc:339: // Don't
create the store now if there are no concrete policies configured
On 2013/11/25 14:24:02, bartfab wrote:
> Nit: What do you mean by "concrete policies"? Do you mean none of the policies
> are set; none of the policies have values?

Yes; removed the "concrete" since it was just confusing.

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
File chrome/browser/extensions/api/storage/managed_value_store_cache.h (right):

https://codereview.chromium.org/78953002/diff/290002/chrome/browser/extension...
chrome/browser/extensions/api/storage/managed_value_store_cache.h:76: bool
HasStore(const std::string& extension_id);
On 2013/11/25 14:24:02, bartfab wrote:
> Nit: const

Done.

[commit-bot: I haz the power, 2013-11-25 15:40:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/joaodasilva@chromium.org/78953002/450001

[commit-bot: I haz the power, 2013-11-25 18:44:59]

Change committed as 237111