base: Remove using declaration of FundamentalValue as it's no longer necessary.

chrome/browser/extensions/extension_file_browser_private_api.cc

Index: chrome/browser/extensions/extension_file_browser_private_api.cc
diff --git a/chrome/browser/extensions/extension_file_browser_private_api.cc b/chrome/browser/extensions/extension_file_browser_private_api.cc
index eafd1130786db870773765a492837dbfe5d5a972..f8d372a04160276e47c8af7fe36996f409c78fa3 100644
--- a/chrome/browser/extensions/extension_file_browser_private_api.cc
+++ b/chrome/browser/extensions/extension_file_browser_private_api.cc
@@ -233,7 +233,7 @@ void UpdateFileHandlerUsageStats(Profile* profile, const std::string& task_id) {
   DictionaryPrefUpdate prefs_usage_update(profile->GetPrefs(),
       prefs::kLastUsedFileBrowserHandlers);
   prefs_usage_update->SetWithoutPathExpansion(task_id,
-      new FundamentalValue(
+      new base::FundamentalValue(
           static_cast<int>(base::Time::Now().ToInternalValue()/
                            base::Time::kMicrosecondsPerSecond)));
 }
@@ -798,7 +798,7 @@ bool ExecuteTasksFileBrowserFunction::InitiateFileTaskExecution(
           source_url_,
           task_id,
           file_urls));
-  result_.reset(new FundamentalValue(true));
+  result_.reset(new base::FundamentalValue(true));
   return true;
 }