Move PathIsWritable, DirectoryExists, ContentsEqual, and TextContentsEqual to the base namespace.

chrome/browser/diagnostics/recon_diagnostics.cc

Index: chrome/browser/diagnostics/recon_diagnostics.cc
diff --git a/chrome/browser/diagnostics/recon_diagnostics.cc b/chrome/browser/diagnostics/recon_diagnostics.cc
index f2043e5262a721b9bef3556ab35d33bb0c53aff5..059d6fc0009ccd47fc514b3c3fef9f85687a7f95 100644
--- a/chrome/browser/diagnostics/recon_diagnostics.cc
+++ b/chrome/browser/diagnostics/recon_diagnostics.cc
@@ -278,7 +278,7 @@ class PathTest : public DiagnosticsTest {
       RecordSuccess("Path exists");
       return true;
     }
-    if (!file_util::PathIsWritable(dir_or_file)) {
+    if (!base::PathIsWritable(dir_or_file)) {
       RecordFailure(DIAG_RECON_NOT_WRITABLE,
                     "Path is not writable: " +
                         UTF16ToUTF8(dir_or_file.LossyDisplayName()));