Implement API features for the Extension API feature system

chrome/common/extensions/api/extension_api.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_EXTENSIONS_API_EXTENSION_API_H_
 #define CHROME_COMMON_EXTENSIONS_API_EXTENSION_API_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 19 matching lines @@
 namespace extensions {
 
 class Extension;
 class Feature;
 
 // C++ Wrapper for the JSON API definitions in chrome/common/extensions/api/.
 //
 // WARNING: This class is accessed on multiple threads in the browser process
 // (see ExtensionFunctionDispatcher). No state should be modified after
 // construction.
-class ExtensionAPI : public FeatureProvider {
+class ExtensionAPI {
  public:
   // Returns a single shared instance of this class. This is the typical use
   // case in Chrome.
   //
   // TODO(aa): Make this const to enforce thread-safe usage.
   static ExtensionAPI* GetSharedInstance();
 
   // Creates a new instance configured the way ExtensionAPI typically is in
   // Chrome. Use the default constructor to get a clean instance.
   static ExtensionAPI* CreateWithDefaultConfiguration();
@@ skipping 30 matching lines @@
   // extension process. They cannot be called from extension code running in
   // content scripts, or other low-privileged contexts.
   bool IsPrivileged(const std::string& name);
 
   // Gets the schema for the extension API with namespace |full_name|.
   // Ownership remains with this object.
   const base::DictionaryValue* GetSchema(const std::string& full_name);
 
   std::set<std::string> GetAllAPINames();
 
-  // Gets a Feature object describing the API with the specified |full_name|.
-  // This can be either an API namespace (like history, or
-  // experimental.bookmarks), or it can be an individual function or event.
-  virtual Feature* GetFeature(const std::string& full_name) OVERRIDE;
-
   // Splits a full name from the extension API into its API and child name
   // parts. Some examples:
   //
   // "bookmarks.create" -> ("bookmarks", "create")
   // "experimental.input.ui.cursorUp" -> ("experimental.input.ui", "cursorUp")
   // "storage.sync.set" -> ("storage", "sync.get")
   // "<unknown-api>.monkey" -> ("", "")
   //
   // The |child_name| parameter can be be NULL if you don't need that part.
   std::string GetAPINameFromFullName(const std::string& full_name,
                                      std::string* child_name);
 
   void InitDefaultConfiguration();
 
+  // Gets a feature from any dependency provider registered with ExtensionAPI.
+  Feature* GetFeatureDependency(const std::string& dependency_name);

[not at google - send to devlin, 2013/03/26 00:34:48]

This doesn't appear to be used outside of this class, so it can be private.

[cduvall, 2013/03/26 19:24:05]

It's used in the unit test.

+
  private:
   friend struct DefaultSingletonTraits<ExtensionAPI>;
 
   // Loads a schema.
   void LoadSchema(const std::string& name, const base::StringPiece& schema);
 
   // Returns true if the function or event under |namespace_node| with
   // the specified |child_name| is privileged, or false otherwise. If the name
   // is not found, defaults to privileged.
   bool IsChildNamePrivileged(const base::DictionaryValue* namespace_node,
@@ skipping 10 matching lines @@
   // The extension or URL may not be relevant to all contexts, and may be left
   // NULL/empty.
   bool IsNonFeatureAPIAvailable(const std::string& name,
                                 Feature::Context context,
                                 const Extension* extension,
                                 const GURL& url);
 
   // Returns true if the API uses the feature system.
   bool UsesFeatureSystem(const std::string& full_name);
 
-  // Gets a feature from any dependency provider.
-  Feature* GetFeatureDependency(const std::string& dependency_name);
-
-  // Adds dependent schemas to |out| as determined by the "dependencies"
-  // property.
-  // TODO(aa): Consider making public and adding tests.
-  void ResolveDependencies(std::set<std::string>* out);
-
-  // Adds any APIs listed in "dependencies" found in the schema for |api_name|
-  // but not in |excluding| to |out|.
-  void GetMissingDependencies(
-      const std::string& api_name,
-      const std::set<std::string>& excluding,
-      std::set<std::string>* out);
+  // Attempts to get a feature from any dependency provider, and returns NULL
+  // if the feature could not be found.
+  Feature* TryGetFeatureDependency(const std::string& dependency_name);
 
   // Checks if an API is *entirely* privileged. This won't include APIs such as
   // "storage" which is entirely unprivileged, nor "extension" which has
   // unprivileged components.
   bool IsPrivilegedAPI(const std::string& name);
 
   // Map from each API that hasn't been loaded yet to the schema which defines
   // it. Note that there may be multiple APIs per schema.
   typedef std::map<std::string, base::StringPiece> UnloadedSchemaMap;
   UnloadedSchemaMap unloaded_schemas_;
@@ skipping 18 matching lines @@
   // FeatureProviders used for resolving dependencies.
   typedef std::map<std::string, FeatureProvider*> FeatureProviderMap;
   FeatureProviderMap dependency_providers_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionAPI);
 };
 
 }  // extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_API_EXTENSION_API_H_