Add explicit base namespace to string16 users.

chrome/common/mac/app_mode_chrome_locator_unittest.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/common/mac/app_mode_chrome_locator.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 25 matching lines @@
 
 TEST(ChromeLocatorTest, FindNonExistentBundle) {
   base::FilePath dummy;
   EXPECT_FALSE(app_mode::FindBundleById(@"this.doesnt.exist", &dummy));
 }
 
 TEST(ChromeLocatorTest, GetNonExistentBundleInfo) {
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
 
-  string16 raw_version;
+  base::string16 raw_version;
   base::FilePath version_path;
   base::FilePath framework_path;
   EXPECT_FALSE(app_mode::GetChromeBundleInfo(temp_dir.path(),
       &raw_version, &version_path, &framework_path));
 }
 
 TEST(ChromeLocatorTest, GetChromeBundleInfo) {
   using app_mode::GetChromeBundleInfo;
 
   base::FilePath chrome_bundle_path;
   GetChromeBundlePath(&chrome_bundle_path);
   ASSERT_TRUE(base::DirectoryExists(chrome_bundle_path));
 
-  string16 raw_version;
+  base::string16 raw_version;
   base::FilePath version_path;
   base::FilePath framework_path;
   EXPECT_TRUE(GetChromeBundleInfo(chrome_bundle_path,
       &raw_version, &version_path, &framework_path));
   EXPECT_GT(raw_version.size(), 0U);
   EXPECT_TRUE(base::DirectoryExists(version_path));
   EXPECT_TRUE(base::PathExists(framework_path));
 }