base: Move MemoryMappedFile out of file_util.h and into its own header file.

content/common/gpu/media/h264_parser_unittest.cc

Index: content/common/gpu/media/h264_parser_unittest.cc
diff --git a/content/common/gpu/media/h264_parser_unittest.cc b/content/common/gpu/media/h264_parser_unittest.cc
index 7c2a75756eaaa324037bdf8cc6f33749c832c618..2aa9f43e94b2199578e53d0fd6fd08667f8ea093 100644
--- a/content/common/gpu/media/h264_parser_unittest.cc
+++ b/content/common/gpu/media/h264_parser_unittest.cc
@@ -5,7 +5,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "base/command_line.h"
-#include "base/file_util.h"
+#include "base/files/memory_mapped_file.h"
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "content/common/gpu/media/h264_parser.h"
@@ -20,7 +20,7 @@ int num_nalus = 759;
 
 TEST(H264ParserTest, StreamFileParsing) {
   base::FilePath fp(test_stream_filename);
-  file_util::MemoryMappedFile stream;
+  base::MemoryMappedFile stream;
   CHECK(stream.Initialize(fp)) << "Couldn't open stream file: "
                                << test_stream_filename;
   DVLOG(1) << "Parsing file: " << test_stream_filename;