Sandbox the component updater's patcher utility process.

courgette/third_party/bsdiff/bsdiff.h

Index: courgette/third_party/bsdiff/bsdiff.h
diff --git a/courgette/third_party/bsdiff/bsdiff.h b/courgette/third_party/bsdiff/bsdiff.h
index a5da4ec9dd130d267868af0d546f1ed5426f73ca..c1d26c728aa804d483f0d4a22baf9c6603d41350 100644
--- a/courgette/third_party/bsdiff/bsdiff.h
+++ b/courgette/third_party/bsdiff/bsdiff.h
@@ -44,6 +44,7 @@
 
 #include <stdint.h>
 
+#include "base/files/file.h"
 #include "base/files/file_util.h"
 
 namespace courgette {
@@ -76,6 +77,11 @@ BSDiffStatus ApplyBinaryPatch(courgette::SourceStream* old_stream,
                               courgette::SourceStream* patch_stream,
                               courgette::SinkStream* new_stream);
 
+// As above, but simply takes base::Files.
+BSDiffStatus ApplyBinaryPatch(base::File old_stream,
+                              base::File patch_stream,
+                              base::File new_stream);
+
 // As above, but simply takes the file paths.
 BSDiffStatus ApplyBinaryPatch(const base::FilePath& old_stream,
                               const base::FilePath& patch_stream,