Implement declarativeContent API.

chrome/browser/extensions/extension_action.h

Index: chrome/browser/extensions/extension_action.h
diff --git a/chrome/browser/extensions/extension_action.h b/chrome/browser/extensions/extension_action.h
index dacd961ee03bb531df0289fc9037730a03071ccf..943a3eb4ab96f5396c56df700af56b781c3d619a 100644
--- a/chrome/browser/extensions/extension_action.h
+++ b/chrome/browser/extensions/extension_action.h
@@ -220,15 +220,20 @@ class ExtensionAction {
   // care of any appropriate transition animations.  Returns true if
   // the appearance has changed.
   bool SetAppearance(int tab_id, Appearance value);
+  // The declarative appearance overrides a default appearance but is overridden
+  // by an appearance set directly on the tab.
+  void DeclarativeShow(int tab_id);
+  void UndoDeclarativeShow(int tab_id);
+
   // Get the badge visibility for a tab, or the default badge visibility
   // if none was set.
   bool GetIsVisible(int tab_id) const {
-    return GetValue(&appearance_, tab_id) != INVISIBLE;
+    return GetAppearance(tab_id) != INVISIBLE;
   }
 
   // True if the tab's action wants the user's attention.
   bool WantsAttention(int tab_id) const {
-    return GetValue(&appearance_, tab_id) == WANTS_ATTENTION;
+    return GetAppearance(tab_id) == WANTS_ATTENTION;
   }
 
   // Remove all tab-specific state.
@@ -272,17 +277,47 @@ class ExtensionAction {
     (*map)[tab_id] = val;
   }
 
+  template<class Map>
+  static const typename Map::mapped_type* FindOrNull(
+      const Map* map,
+      const typename Map::key_type& key) {
+    typename Map::const_iterator iter = map->find(key);
+    if (iter == map->end())
+      return NULL;
+    return &iter->second;
+  }
+
   template<class T>
   T GetValue(const std::map<int, T>* map, int tab_id) const {
-    typename std::map<int, T>::const_iterator iter = map->find(tab_id);
-    if (iter != map->end()) {
-      return iter->second;
+    if (const T* tab_value = FindOrNull(map, tab_id)) {
+      return *tab_value;
+    } else if (const T* default_value = FindOrNull(map, kDefaultTabId)) {
+      return *default_value;
     } else {
-      iter = map->find(kDefaultTabId);
-      return iter != map->end() ? iter->second : ValueTraits<T>::CreateEmpty();
+      return ValueTraits<T>::CreateEmpty();
     }
   }
 
+  // Gets the appearance of |tab_id|.  Returns the first of: a specific
+  // appearance set on the tab; a declarative appearance set on the tab; the
+  // default appearance set for all tabs; or INVISIBLE.  Don't return this
+  // result to an extension's background page because the declarative state can
+  // leak information about hosts the extension doesn't have permission to
+  // access.
+  Appearance GetAppearance(int tab_id) const {
+    if (const Appearance* tab_appearance = FindOrNull(&appearance_, tab_id))
+      return *tab_appearance;
+
+    if (ContainsKey(declarative_show_count_, tab_id))
+      return ACTIVE;
+
+    if (const Appearance* default_appearance =
+        FindOrNull(&appearance_, kDefaultTabId))
+      return *default_appearance;
+
+    return INVISIBLE;
+  }
+
   // The id for the extension this action belongs to (as defined in the
   // extension manifest).
   const std::string extension_id_;
@@ -299,6 +334,17 @@ class ExtensionAction {
   std::map<int, SkColor> badge_text_color_;
   std::map<int, Appearance> appearance_;
 
+  // Declarative state exists for two reasons: First, we need to hide it from
+  // the extension's background/event page to avoid leaking data from hosts the
+  // extension doesn't have permission to access.  Second, the action's state
+  // gets both reset and given its declarative values in response to a
+  // WebContentsObserver::DidNavigateMainFrame event, and there's no way to set
+  // those up to be called in the right order.
+
+  // Maps tab_id to the number of active (applied-but-not-reverted)
+  // declarativeContent.ShowPageAction actions.
+  std::map<int, int> declarative_show_count_;
+
   // IconAnimations are destroyed by a delayed task on the UI message loop so
   // that even if the Extension and ExtensionAction are destroyed on a non-UI
   // thread, the animation will still only be touched from the UI thread.  This