Remove base::Value::CreateNullValue

chrome/browser/extensions/api/web_navigation/web_navigation_api.cc

Index: chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
diff --git a/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc b/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
index 4064afccb310679ad10d9666380a0bc61225a1cb..2cc3ea482ffbcc34fc93e36105c4e1437ff1e76f 100644
--- a/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
+++ b/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
@@ -7,6 +7,7 @@
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 
 #include "base/lazy_instance.h"
+#include "base/memory/ptr_util.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_constants.h"
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.h"
@@ -476,7 +477,7 @@ ExtensionFunction::ResponseAction WebNavigationGetFrameFunction::Run() {
                                     include_incognito(), nullptr, nullptr,
                                     &web_contents, nullptr) ||
       !web_contents) {
-    return RespondNow(OneArgument(base::Value::CreateNullValue()));
+    return RespondNow(OneArgument(base::MakeUnique<base::Value>()));
   }
 
   WebNavigationTabObserver* observer =
@@ -490,11 +491,11 @@ ExtensionFunction::ResponseAction WebNavigationGetFrameFunction::Run() {
       ExtensionApiFrameIdMap::Get()->GetRenderFrameHostById(web_contents,
                                                             frame_id);
   if (!frame_navigation_state.IsValidFrame(render_frame_host))
-    return RespondNow(OneArgument(base::Value::CreateNullValue()));
+    return RespondNow(OneArgument(base::MakeUnique<base::Value>()));
 
   GURL frame_url = frame_navigation_state.GetUrl(render_frame_host);
   if (!frame_navigation_state.IsValidUrl(frame_url))
-    return RespondNow(OneArgument(base::Value::CreateNullValue()));
+    return RespondNow(OneArgument(base::MakeUnique<base::Value>()));
 
   GetFrame::Results::Details frame_details;
   frame_details.url = frame_url.spec();
@@ -516,7 +517,7 @@ ExtensionFunction::ResponseAction WebNavigationGetAllFramesFunction::Run() {
                                     include_incognito(), nullptr, nullptr,
                                     &web_contents, nullptr) ||
       !web_contents) {
-    return RespondNow(OneArgument(base::Value::CreateNullValue()));
+    return RespondNow(OneArgument(base::MakeUnique<base::Value>()));
   }
 
   WebNavigationTabObserver* observer =