Move WriteFile and WriteFileDescriptor from file_util to base namespace.

chrome/browser/extensions/updater/local_extension_cache_unittest.cc

Index: chrome/browser/extensions/updater/local_extension_cache_unittest.cc
diff --git a/chrome/browser/extensions/updater/local_extension_cache_unittest.cc b/chrome/browser/extensions/updater/local_extension_cache_unittest.cc
index e4f4636ae70066269ab4e3b7a7ab8f8aab6f584d..f232d5ea3de85d4e456156c93229d22191f61eb1 100644
--- a/chrome/browser/extensions/updater/local_extension_cache_unittest.cc
+++ b/chrome/browser/extensions/updater/local_extension_cache_unittest.cc
@@ -79,7 +79,7 @@ class LocalExtensionCacheTest : public testing::Test {
                   size_t size,
                   const base::Time& timestamp) {
     std::string data(size, 0);
-    EXPECT_EQ(file_util::WriteFile(file, data.data(), data.size()), int(size));
+    EXPECT_EQ(base::WriteFile(file, data.data(), data.size()), int(size));
     EXPECT_TRUE(base::TouchFile(file, timestamp, timestamp));
   }