Move StartsWith[ASCII] to base namespace.

chrome/browser/media_galleries/fileapi/native_media_file_util.cc

Index: chrome/browser/media_galleries/fileapi/native_media_file_util.cc
diff --git a/chrome/browser/media_galleries/fileapi/native_media_file_util.cc b/chrome/browser/media_galleries/fileapi/native_media_file_util.cc
index 79dc4f0d205dca4afa5628b3c9b587a23cfe2207..87acf8caf0f3f637e900c98ac0ba97ef4eb84e2e 100644
--- a/chrome/browser/media_galleries/fileapi/native_media_file_util.cc
+++ b/chrome/browser/media_galleries/fileapi/native_media_file_util.cc
@@ -37,9 +37,9 @@ base::File::Error IsMediaHeader(const char* buf, size_t length) {
   if (!net::SniffMimeTypeFromLocalData(buf, length, &mime_type))
     return base::File::FILE_ERROR_SECURITY;
 
-  if (StartsWithASCII(mime_type, "image/", true) ||
-      StartsWithASCII(mime_type, "audio/", true) ||
-      StartsWithASCII(mime_type, "video/", true) ||
+  if (base::StartsWithASCII(mime_type, "image/", true) ||
+      base::StartsWithASCII(mime_type, "audio/", true) ||
+      base::StartsWithASCII(mime_type, "video/", true) ||
       mime_type == "application/x-shockwave-flash") {
     return base::File::FILE_OK;
   }