Implement clipboardRead/Write content capabilities

extensions/renderer/dispatcher.h

Index: extensions/renderer/dispatcher.h
diff --git a/extensions/renderer/dispatcher.h b/extensions/renderer/dispatcher.h
index fa3a784103029ed17beab9df1ffd96f0b85dedd6..021fc943157202a9e092501fb8dc1edca0cf9adf 100644
--- a/extensions/renderer/dispatcher.h
+++ b/extensions/renderer/dispatcher.h
@@ -220,6 +220,14 @@ class Dispatcher : public content::RenderProcessObserver,
   void RegisterNativeHandlers(ModuleSystem* module_system,
                               ScriptContext* context);
 
+  // Determines if a ScriptContext can connect to any externally_connectable-
+  // enabled extension.
+  bool IsRuntimeAvailableToContext(ScriptContext* context);
+
+  // Updates a web page context with any content capabilities granted by active
+  // extensions.
+  void UpdateContentCapabilities(ScriptContext* context);
+
   // Inserts static source code into |source_map_|.
   void PopulateSourceMap();