Move ReadFileToString to the base namespace.

BUG=

Review URL: https://codereview.chromium.org/19579005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@220612 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/net/base/file_stream_unittest.cc b/net/base/file_stream_unittest.cc
index 4be58b7..a091e7a4 100644
--- a/net/base/file_stream_unittest.cc
+++ b/net/base/file_stream_unittest.cc
@@ -1017,7 +1017,7 @@
 
   // Read in the contents and make sure we get back what we expected.
   std::string read_contents;
-  EXPECT_TRUE(file_util::ReadFileToString(temp_file_path(), &read_contents));
+  EXPECT_TRUE(base::ReadFileToString(temp_file_path(), &read_contents));
 
   EXPECT_EQ("01230123", read_contents);
 }