Move more file_util functions to base namespace.

This moves DevicePathToDriveLetterPath, NormalizeToNativeFilePath, IsLink, and GetFileInfo.

This also removes some explicit "base::" usage in base files I touched.

TBR=jam

Review URL: https://codereview.chromium.org/105293002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238763 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/file_util.cc b/base/file_util.cc
index 1198636..6140cea 100644
--- a/base/file_util.cc
+++ b/base/file_util.cc
@@ -167,7 +167,7 @@
 
 bool GetFileSize(const FilePath& file_path, int64* file_size) {
   PlatformFileInfo info;
-  if (!file_util::GetFileInfo(file_path, &info))
+  if (!GetFileInfo(file_path, &info))
     return false;
   *file_size = info.size;
   return true;