Move IsStringASCII/UTF8 to base namespace.

chrome/browser/extensions/api/serial/serial_connection.cc

Index: chrome/browser/extensions/api/serial/serial_connection.cc
diff --git a/chrome/browser/extensions/api/serial/serial_connection.cc b/chrome/browser/extensions/api/serial/serial_connection.cc
index 281cddaf1f72c01261aa6d7cca8bdaf33b41a62c..64772f3fc78093858d9fd21957eec0e3ea3a3c94 100644
--- a/chrome/browser/extensions/api/serial/serial_connection.cc
+++ b/chrome/browser/extensions/api/serial/serial_connection.cc
@@ -168,7 +168,7 @@ void SerialConnection::StartOpen() {
   // It's the responsibility of the API wrapper around SerialConnection to
   // validate the supplied path against the set of valid port names, and
   // it is a reasonable assumption that serial port names are ASCII.
-  DCHECK(IsStringASCII(port_));
+  DCHECK(base::IsStringASCII(port_));
   base::FilePath path(
       base::FilePath::FromUTF8Unsafe(MaybeFixUpPortName(port_)));
   int flags = base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ |