Move more file_util functions to base namespace.

media/webm/chromeos/webm_encoder.cc

Index: media/webm/chromeos/webm_encoder.cc
diff --git a/media/webm/chromeos/webm_encoder.cc b/media/webm/chromeos/webm_encoder.cc
index da1f1767b7d58ff804b145b04d057a6cc41a06ad..059f9c6fef633ff1adadebc025e9eb28b9964b11 100644
--- a/media/webm/chromeos/webm_encoder.cc
+++ b/media/webm/chromeos/webm_encoder.cc
@@ -157,7 +157,7 @@ bool WebmEncoder::EncodeFromSprite(const SkBitmap& sprite,
 }
 
 bool WebmEncoder::WriteWebmHeader() {
-  output_ = file_util::OpenFile(output_path_, "wb");
+  output_ = base::OpenFile(output_path_, "wb");
   if (!output_)
     return false;
 
@@ -251,7 +251,7 @@ bool WebmEncoder::WriteWebmFooter() {
   EndSubElement();  // Cluster
   EndSubElement();  // Segment
   DCHECK(ebml_sub_elements_.empty());
-  return file_util::CloseFile(output_) && !has_errors_;
+  return base::CloseFile(output_) && !has_errors_;
 }
 
 void WebmEncoder::StartSubElement(unsigned long class_id) {