[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/extension_function_dispatcher.cc

 // Copyright 2014 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.
 
 #include "extensions/browser/extension_function_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 187 matching lines @@
 
   base::WeakPtr<ExtensionFunctionDispatcher> dispatcher_;
   content::RenderViewHost* render_view_host_;
   base::WeakPtrFactory<UIThreadResponseCallbackWrapper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UIThreadResponseCallbackWrapper);
 };
 
 WindowController*
 ExtensionFunctionDispatcher::Delegate::GetExtensionWindowController() const {
-  return NULL;
+  return nullptr;
 }
 
 content::WebContents*
 ExtensionFunctionDispatcher::Delegate::GetAssociatedWebContents() const {
-  return NULL;
+  return nullptr;
 }
 
 content::WebContents*
 ExtensionFunctionDispatcher::Delegate::GetVisibleWebContents() const {
   return GetAssociatedWebContents();
 }
 
 void ExtensionFunctionDispatcher::GetAllFunctionNames(
     std::vector<std::string>* names) {
   ExtensionFunctionRegistry::GetInstance()->GetAllNames(names);
@@ skipping 70 matching lines @@
     tracked_objects::ScopedProfile scoped_profile(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(function->name()),
         tracked_objects::ScopedProfile::ENABLED);
     function->Run()->Execute();
   } else {
     function->OnQuotaExceeded(violation_error);
   }
 }
 
 ExtensionFunctionDispatcher::ExtensionFunctionDispatcher(
-    content::BrowserContext* browser_context,
-    Delegate* delegate)
-    : browser_context_(browser_context),
-      delegate_(delegate) {
+    content::BrowserContext* browser_context)
+    : browser_context_(browser_context) {
 }
 
 ExtensionFunctionDispatcher::~ExtensionFunctionDispatcher() {
 }
 
 void ExtensionFunctionDispatcher::Dispatch(
     const ExtensionHostMsg_Request_Params& params,
     RenderViewHost* render_view_host) {
   UIThreadResponseCallbackWrapperMap::const_iterator
       iter = ui_thread_response_callback_wrappers_.find(render_view_host);
@@ skipping 115 matching lines @@
 }
 
 void ExtensionFunctionDispatcher::OnExtensionFunctionCompleted(
     const Extension* extension) {
   if (extension) {
     ProcessManager::Get(browser_context_)
         ->DecrementLazyKeepaliveCount(extension);
   }
 }
 
+WindowController*
+ExtensionFunctionDispatcher::GetExtensionWindowController() const {
+  return delegate_ ? delegate_->GetExtensionWindowController() : nullptr;
+}
+
+content::WebContents*
+ExtensionFunctionDispatcher::GetAssociatedWebContents() const {
+  return delegate_ ? delegate_->GetAssociatedWebContents() : nullptr;
+}
+
+content::WebContents*
+ExtensionFunctionDispatcher::GetVisibleWebContents() const {
+  return delegate_ ? delegate_->GetVisibleWebContents() :
+      GetAssociatedWebContents();
+}
+
 // static
 bool ExtensionFunctionDispatcher::CheckPermissions(
     ExtensionFunction* function,
     const ExtensionHostMsg_Request_Params& params,
     const ExtensionFunction::ResponseCallback& callback) {
   if (!function->HasPermission()) {
     LOG(ERROR) << "Permission denied for " << params.name;
     SendAccessDenied(callback, function->histogram_value());
     return false;
   }
@@ skipping 35 matching lines @@
 // static
 void ExtensionFunctionDispatcher::SendAccessDenied(
     const ExtensionFunction::ResponseCallback& callback,
     functions::HistogramValue histogram_value) {
   base::ListValue empty_list;
   callback.Run(ExtensionFunction::FAILED, empty_list,
                "Access to extension API denied.", histogram_value);
 }
 
 }  // namespace extensions