[Offline Pages] Adds new policy bits and reverse lookup.

components/offline_pages/client_policy_controller.h

Index: components/offline_pages/client_policy_controller.h
diff --git a/components/offline_pages/client_policy_controller.h b/components/offline_pages/client_policy_controller.h
index 55da43d5965dda98ea0196399521d4ac3126ea70..3084fc680b5fd2ef3ef75062122753f9c52c2dd3 100644
--- a/components/offline_pages/client_policy_controller.h
+++ b/components/offline_pages/client_policy_controller.h
@@ -8,7 +8,9 @@
 #include <stdint.h>
 
 #include <map>
+#include <memory>
 #include <string>
+#include <vector>
 
 #include "base/time/time.h"
 #include "components/offline_pages/offline_page_client_policy.h"
@@ -38,12 +40,28 @@ class ClientPolicyController {
 
   // Returns whether pages for |name_space| are shown in Download UI.
   bool IsSupportedByDownload(const std::string& name_space) const;
+  const std::vector<std::string>& GetNamespacesWithDownloadSupport();

[chili, 2016/09/23 23:52:43]

should these methods be const as well?

[dewittj, 2016/09/23 23:55:55]

Because they are memoizing they are not actually const.

[chili, 2016/09/24 00:00:19]

Ah oops forgot about the memoizing bit. darn ^_^

[Dmitry Titov, 2016/09/24 00:09:29]

I think naming-wise, those "get namespaces" methods should follow the "isFoo"
methods, for example in this case, 
GetNamespacesWithDownloadSupport -> GetNamspacesSupportedByDownload

[dewittj, 2016/09/26 23:00:31]

Done.

+
+  // Returns whether pages for |name_space| are shown in recent tabs UI,
+  // currently only available on NTP.
+  bool IsRecentTab(const std::string& name_space) const;

[Dmitry Titov, 2016/09/24 00:09:29]

What is this feature? Can't understand from the comment or the name... Is this
"recently visited sites" on NTP? If so, then maybe call it 
IsShownAsRecentlyVisitedSite ?

[dewittj, 2016/09/26 23:00:31]

Done.

+  const std::vector<std::string>& GetNamespacesForRecentTabs();
+
+  // Returns whether pages for |name_space| should never be shown outside the
+  // tab they were generated in.
+  bool ShouldOnlyBeShownInOriginalTab(const std::string& name_space) const;

[Dmitry Titov, 2016/09/24 00:09:29]

Naming suggestion: IsRestrictedToOriginalTab

[dewittj, 2016/09/26 23:00:31]

Done.

+  const std::vector<std::string>& GetNamespacesToShowInOriginalTab();
 
  private:
   // The map from name_space to a client policy. Will be generated
   // as pre-defined values for now.
   std::map<std::string, OfflinePageClientPolicy> policies_;
 
+  // Memoizing results.
+  std::unique_ptr<std::vector<std::string>> download_namespace_cache_;
+  std::unique_ptr<std::vector<std::string>> recent_tab_namespace_cache_;
+  std::unique_ptr<std::vector<std::string>> show_in_original_tab_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(ClientPolicyController);
 };