content: Use stl utilities from the base namespace

content/shell/browser/layout_test/blink_test_controller.cc

Index: content/shell/browser/layout_test/blink_test_controller.cc
diff --git a/content/shell/browser/layout_test/blink_test_controller.cc b/content/shell/browser/layout_test/blink_test_controller.cc
index 9aca502cd1995794db6989e01544b27220b6325b..4e6a1ede9a1c663d8708e5f09251d95a3ebad156 100644
--- a/content/shell/browser/layout_test/blink_test_controller.cc
+++ b/content/shell/browser/layout_test/blink_test_controller.cc
@@ -597,7 +597,8 @@ void BlinkTestController::HandleNewRenderFrameHost(RenderFrameHost* frame) {
   }
 
   // Is this the 1st time this renderer contains parts of the main test window?
-  if (main_window && !ContainsKey(main_window_render_process_hosts_, process)) {
+  if (main_window &&
+      !base::ContainsKey(main_window_render_process_hosts_, process)) {
     main_window_render_process_hosts_.insert(process);
 
     // Make sure the new renderer process has a test configuration shared with