clang/win: Let remaining chromium_code targets build with -Wextra.

chrome/common/importer/firefox_importer_utils_win.cc

Index: chrome/common/importer/firefox_importer_utils_win.cc
diff --git a/chrome/common/importer/firefox_importer_utils_win.cc b/chrome/common/importer/firefox_importer_utils_win.cc
index 7cfbc508e46a6e8954b3fbd936fba472547ec36f..47486d11c7b740a6f60a4800e9885cae6f521a7e 100644
--- a/chrome/common/importer/firefox_importer_utils_win.cc
+++ b/chrome/common/importer/firefox_importer_utils_win.cc
@@ -32,9 +32,8 @@ int GetCurrentFirefoxMajorVersionFromRegistry() {
   // When installing Firefox with admin account, the product keys will be
   // written under HKLM\Mozilla. Otherwise it the keys will be written under
   // HKCU\Mozilla.
-  for (int i = 0; i < arraysize(kFireFoxRegistryPaths); ++i) {
-    base::win::RegKey reg_key(kFireFoxRegistryPaths[i], kFirefoxPath,
-                              KEY_READ);
+  for (const HKEY kFireFoxRegistryPath : kFireFoxRegistryPaths) {
+    base::win::RegKey reg_key(kFireFoxRegistryPath, kFirefoxPath, KEY_READ);
 
     LONG result = reg_key.ReadValue(kCurrentVersion, ver_buffer,
                                     &ver_buffer_length, NULL);