[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/extension_function_dispatcher.h

Index: extensions/browser/extension_function_dispatcher.h
diff --git a/extensions/browser/extension_function_dispatcher.h b/extensions/browser/extension_function_dispatcher.h
index 9224bbde5134518e72365f597c900e8b0ec094c1..2764449af85bbe1e7ed7cd1957f6438fb647d033 100644
--- a/extensions/browser/extension_function_dispatcher.h
+++ b/extensions/browser/extension_function_dispatcher.h
@@ -90,16 +90,12 @@ class ExtensionFunctionDispatcher
       const ExtensionHostMsg_Request_Params& params);
 
   // Public constructor. Callers must ensure that:
-  // - |delegate| outlives this object.
   // - This object outlives any RenderViewHost's passed to created
   //   ExtensionFunctions.
-  ExtensionFunctionDispatcher(content::BrowserContext* browser_context,
-                              Delegate* delegate);
-
+  explicit ExtensionFunctionDispatcher(
+      content::BrowserContext* browser_context);
   ~ExtensionFunctionDispatcher();
 
-  Delegate* delegate() { return delegate_; }
-
   // Message handlers.
   // The response is sent to the corresponding render view in an
   // ExtensionMsg_Response message.
@@ -111,9 +107,18 @@ class ExtensionFunctionDispatcher
   // a response (if any) to the extension.
   void OnExtensionFunctionCompleted(const Extension* extension);
 
+  // See the Delegate class for documentation on these methods.
+  // TODO(devlin): None of these belong here. We should kill
+  // ExtensionFunctionDispatcher::Delegate.
+  WindowController* GetExtensionWindowController() const;
+  content::WebContents* GetAssociatedWebContents() const;
+  content::WebContents* GetVisibleWebContents() const;
+
   // The BrowserContext that this dispatcher is associated with.
   content::BrowserContext* browser_context() { return browser_context_; }
 
+  void set_delegate(Delegate* delegate) { delegate_ = delegate; }
+
  private:
   // For a given RenderViewHost instance, UIThreadResponseCallbackWrapper
   // creates ExtensionFunction::ResponseCallback instances which send responses