Move small c/b/extensions classes into extensions namespace no.1

chrome/browser/extensions/convert_web_app_browsertest.cc

Index: chrome/browser/extensions/convert_web_app_browsertest.cc
diff --git a/chrome/browser/extensions/convert_web_app_browsertest.cc b/chrome/browser/extensions/convert_web_app_browsertest.cc
index 858c69e13eba695fe73d6bda8e4e0b0a9822de50..393176d6678cecc17ea8fe4b82e9d33d945b6807 100644
--- a/chrome/browser/extensions/convert_web_app_browsertest.cc
+++ b/chrome/browser/extensions/convert_web_app_browsertest.cc
@@ -18,7 +18,7 @@
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
 
-using extensions::APIPermission;
+namespace extensions {
 
 class ExtensionFromWebAppTest
     : public InProcessBrowserTest, public content::NotificationObserver {
@@ -27,7 +27,7 @@ class ExtensionFromWebAppTest
   }
 
   std::string expected_extension_id_;
-  const extensions::Extension* installed_extension_;
+  const Extension* installed_extension_;
 
  private:
   // InProcessBrowserTest
@@ -40,8 +40,8 @@ class ExtensionFromWebAppTest
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) {
     if (type == chrome::NOTIFICATION_EXTENSION_INSTALLED) {
-      const extensions::Extension* extension =
-          content::Details<const extensions::Extension>(details).ptr();
+      const Extension* extension =
+          content::Details<const Extension>(details).ptr();
       if (extension->id() == expected_extension_id_) {
         installed_extension_ = extension;
         MessageLoopForUI::current()->Quit();
@@ -89,3 +89,5 @@ IN_PROC_BROWSER_TEST_F(ExtensionFromWebAppTest, Basic) {
   EXPECT_EQ("icons/128.png", installed_extension_->icons().Get(
       128, ExtensionIconSet::MATCH_EXACTLY));
 }
+
+}  // namespace extensions