Make UTF16ToASCII and UTF16TOUTF8 take a StringPiece

content/renderer/media/android/webmediaplayer_android.cc

Index: content/renderer/media/android/webmediaplayer_android.cc
diff --git a/content/renderer/media/android/webmediaplayer_android.cc b/content/renderer/media/android/webmediaplayer_android.cc
index eeeaf1d6b5ee32c7fdb92564b19aa9be9062c2b7..e04d8f436f37a02e8306469be59bc6b656fbbfd5 100644
--- a/content/renderer/media/android/webmediaplayer_android.cc
+++ b/content/renderer/media/android/webmediaplayer_android.cc
@@ -1443,8 +1443,9 @@ const gfx::RectF WebMediaPlayerAndroid::GetBoundaryRectangle() {
 // Convert a WebString to ASCII, falling back on an empty string in the case
 // of a non-ASCII string.
 static std::string ToASCIIOrEmpty(const blink::WebString& string) {
-  return base::IsStringASCII(string) ? base::UTF16ToASCII(string)
-                                     : std::string();
+  return base::IsStringASCII(string)
+      ? base::UTF16ToASCII(base::StringPiece16(string))
+      : std::string();
 }
 
 // Helper functions to report media EME related stats to UMA. They follow the