Add base:: to string16s in chrome/.

chrome/app/app_mode_loader_mac.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.
 
 // On Mac, shortcuts can't have command-line arguments. Instead, produce small
 // app bundles which locate the Chromium framework and load it, passing the
 // appropriate data. This is the code for such an app bundle. It should be kept
 // minimal and do as little work as possible (with as much work done on
 // framework side as possible).
 
@@ skipping 45 matching lines @@
   if (!found_bundle) {
     // If no such bundle path exists, try to search by bundle ID.
     if (!app_mode::FindBundleById(cr_bundle_id, &cr_bundle_path)) {
       // TODO(jeremy): Display UI to allow user to manually locate the Chrome
       // bundle.
       LOG(FATAL) << "Failed to locate bundle by identifier";
     }
   }
 
   // ** 2: Read information from the Chrome bundle.
-  string16 raw_version_str;
+  base::string16 raw_version_str;
   base::FilePath version_path;
   base::FilePath framework_shlib_path;
   if (!app_mode::GetChromeBundleInfo(cr_bundle_path, &raw_version_str,
           &version_path, &framework_shlib_path)) {
     LOG(FATAL) << "Couldn't ready Chrome bundle info";
   }
 
   // ** 3: Fill in ChromeAppModeInfo.
   info->chrome_outer_bundle_path = cr_bundle_path;
   info->chrome_versioned_path = version_path;
@@ skipping 44 matching lines @@
 
   typedef int (*StartFun)(const app_mode::ChromeAppModeInfo*);
   StartFun ChromeAppModeStart = (StartFun)dlsym(cr_dylib, "ChromeAppModeStart");
   CHECK(ChromeAppModeStart) << "couldn't get entry point";
 
   // Exit instead of returning to avoid the the removal of |main()| from stack
   // backtraces under tail call optimization.
   int rv = ChromeAppModeStart(&info);
   exit(rv);
 }