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

components/offline_pages/client_policy_controller.cc

Index: components/offline_pages/client_policy_controller.cc
diff --git a/components/offline_pages/client_policy_controller.cc b/components/offline_pages/client_policy_controller.cc
index d66193350808e2f1baa03d228115013afa20eb3b..34f7d4c3db2d51fb689ebf25d65c79c8178b0771 100644
--- a/components/offline_pages/client_policy_controller.cc
+++ b/components/offline_pages/client_policy_controller.cc
@@ -6,6 +6,7 @@
 
 #include <utility>
 
+#include "base/memory/ptr_util.h"
 #include "base/time/time.h"
 #include "components/offline_pages/client_namespace_constants.h"
 
@@ -21,9 +22,13 @@ ClientPolicyController::ClientPolicyController() {
       MakePolicy(kBookmarkNamespace, LifetimeType::TEMPORARY,
                  base::TimeDelta::FromDays(7), kUnlimitedPages, 1)));
   policies_.insert(std::make_pair(
-      kLastNNamespace, MakePolicy(kLastNNamespace, LifetimeType::TEMPORARY,
-                                  base::TimeDelta::FromDays(2), kUnlimitedPages,
-                                  kUnlimitedPages)));
+      kLastNNamespace,
+      OfflinePageClientPolicyBuilder(kLastNNamespace, LifetimeType::TEMPORARY,
+                                     kUnlimitedPages, kUnlimitedPages)
+          .SetExpirePeriod(base::TimeDelta::FromDays(2))
+          .SetIsSupportedByRecentTabs(true)

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

This set of bits looks conflicting? If we only can show the page in original
tab, it makes less sense to show it in some list of recently visited sites,
because it implies that user cna click on items in that list to re-open the
snapshots, and we can't do that once the tab is navigated/closed...

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

These are not strictly conflicting.  Imagine if we ship last-n = n; then that
would be supported by recent tabs, but not shown in original tab.

I think NTP plans to get the wiring set up for switching to a tab that has an
offline copy.  Something like iterating the current list of tabs and
intersecting with the recent tabs list by tab ID

+          .SetIsOnlyShownInOriginalTab(true)
+          .Build()));
   policies_.insert(std::make_pair(
       kAsyncNamespace,
       OfflinePageClientPolicyBuilder(kAsyncNamespace, LifetimeType::PERSISTENT,
@@ -89,4 +94,54 @@ bool ClientPolicyController::IsSupportedByDownload(
   return GetPolicy(name_space).feature_policy.is_supported_by_download;
 }
 
+const std::vector<std::string>&
+ClientPolicyController::GetNamespacesWithDownloadSupport() {
+  if (download_namespace_cache_)
+    return *download_namespace_cache_;
+
+  download_namespace_cache_ = base::MakeUnique<std::vector<std::string>>();
+  for (const auto& policy_item : policies_) {
+    if (policy_item.second.feature_policy.is_supported_by_download)
+      download_namespace_cache_->emplace_back(policy_item.first);
+  }
+  return *download_namespace_cache_;
+}
+
+bool ClientPolicyController::IsRecentTab(const std::string& name_space) const {
+  return GetPolicy(name_space).feature_policy.is_supported_by_recent_tabs;
+}
+
+const std::vector<std::string>&
+ClientPolicyController::GetNamespacesForRecentTabs() {
+  if (recent_tab_namespace_cache_)
+    return *recent_tab_namespace_cache_;
+
+  recent_tab_namespace_cache_ = base::MakeUnique<std::vector<std::string>>();
+  for (const auto& policy_item : policies_) {
+    if (policy_item.second.feature_policy.is_supported_by_recent_tabs)
+      recent_tab_namespace_cache_->emplace_back(policy_item.first);
+  }
+
+  return *recent_tab_namespace_cache_;
+}
+
+bool ClientPolicyController::ShouldOnlyBeShownInOriginalTab(
+    const std::string& name_space) const {
+  return GetPolicy(name_space).feature_policy.only_shown_in_original_tab;
+}
+
+const std::vector<std::string>&
+ClientPolicyController::GetNamespacesToShowInOriginalTab() {
+  if (show_in_original_tab_cache_)
+    return *show_in_original_tab_cache_;
+
+  show_in_original_tab_cache_ = base::MakeUnique<std::vector<std::string>>();
+  for (const auto& policy_item : policies_) {
+    if (policy_item.second.feature_policy.only_shown_in_original_tab)
+      show_in_original_tab_cache_->emplace_back(policy_item.first);
+  }
+
+  return *show_in_original_tab_cache_;
+}
+
 }  // namespace offline_pages