Move Extension into extensions namespace

chrome/browser/download/chrome_download_manager_delegate.cc

Index: chrome/browser/download/chrome_download_manager_delegate.cc
diff --git a/chrome/browser/download/chrome_download_manager_delegate.cc b/chrome/browser/download/chrome_download_manager_delegate.cc
index 56c36135e8651256f39704df4a547bdd4e5f4f24..68c2ca9a7c9d3a88680cc92ba4559aa25f1a244d 100644
--- a/chrome/browser/download/chrome_download_manager_delegate.cc
+++ b/chrome/browser/download/chrome_download_manager_delegate.cc
@@ -92,7 +92,7 @@ bool ChromeDownloadManagerDelegate::IsExtensionDownload(
   if (item->PromptUserForSaveLocation())
     return false;
 
-  if ((item->GetMimeType() != Extension::kMimeType) &&
+  if ((item->GetMimeType() != extensions::Extension::kMimeType) &&
       !UserScript::IsURLUserScript(item->GetURL(), item->GetMimeType())) {
     return false;
   }
@@ -190,7 +190,7 @@ bool ChromeDownloadManagerDelegate::ShouldOpenFileBasedOnExtension(
   FilePath::StringType extension = path.Extension();
   if (extension.empty())
     return false;
-  if (Extension::IsExtension(path))
+  if (extensions::Extension::IsExtension(path))
     return false;
   DCHECK(extension[0] == FilePath::kExtensionSeparator);
   extension.erase(0, 1);