Add base:: to string16s in chrome/.

chrome/installer/util/uninstall_metrics_unittest.cc

Index: chrome/installer/util/uninstall_metrics_unittest.cc
diff --git a/chrome/installer/util/uninstall_metrics_unittest.cc b/chrome/installer/util/uninstall_metrics_unittest.cc
index cfd39c5a6b56c589e00ff56f17317f850f06ee43..fb6ee9de0dfb89b058beb72027623bb01473f0d5 100644
--- a/chrome/installer/util/uninstall_metrics_unittest.cc
+++ b/chrome/installer/util/uninstall_metrics_unittest.cc
@@ -36,7 +36,7 @@ TEST(UninstallMetricsTest, TestExtractUninstallMetrics) {
       "} \n");
 
   // The URL string we expect to be generated from said make-believe file.
-  string16 expected_url_string(
+  base::string16 expected_url_string(
       L"&installation_date2=1235341141"
       L"&last_launch_time_sec=1235341118"
       L"&last_observed_running_time_sec=1235341183"
@@ -48,7 +48,7 @@ TEST(UninstallMetricsTest, TestExtractUninstallMetrics) {
 
   scoped_ptr<Value> root(json_deserializer.Deserialize(NULL, &error_message));
   ASSERT_TRUE(root.get());
-  string16 uninstall_metrics_string;
+  base::string16 uninstall_metrics_string;
 
   EXPECT_TRUE(
       ExtractUninstallMetrics(*static_cast<DictionaryValue*>(root.get()),