update_engine: Remove unused ScopedFileDescriptorCloser.

This was never used and we plan to use chromeos::Streams instead.

BUG=None
TEST=unittest still build and pass.

Change-Id: I42a2d632f07468e9d3b8eee2af74e9456c470ece
Reviewed-on: https://chromium-review.googlesource.com/276986
Reviewed-by: Gilad Arnold <garnold@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/file_descriptor.cc b/file_descriptor.cc
index 5fd18d0..9907a8c 100644
--- a/file_descriptor.cc
+++ b/file_descriptor.cc
@@ -63,18 +63,4 @@
   fd_ = -1;
 }
 
-
-ScopedFileDescriptorCloser::~ScopedFileDescriptorCloser() {
-  if (descriptor_ && descriptor_->IsOpen() && !descriptor_->Close()) {
-    const char* err_str = "file closing failed";
-    if (descriptor_->IsSettingErrno()) {
-      PLOG(ERROR) << err_str;
-    } else {
-      LOG(ERROR) << err_str;
-    }
-    // Abandon the current descriptor, forcing it back to a closed state.
-    descriptor_->Reset();
-  }
-}
-
 }  // namespace chromeos_update_engine
diff --git a/file_descriptor.h b/file_descriptor.h
index 78647de..f2e5caf 100644
--- a/file_descriptor.h
+++ b/file_descriptor.h
@@ -109,21 +109,6 @@
   int fd_;
 };
 
-// A scoped closer for a FileDescriptor object. The destructor of this class
-// invokes the Close() method of the given file descriptor, if it's not in the
-// closed state already. Note, however, that if Close() fails, this class will
-// force a Reset() invocation, which will abandon the current file descriptor.
-class ScopedFileDescriptorCloser {
- public:
-  explicit ScopedFileDescriptorCloser(FileDescriptor* descriptor)
-      : descriptor_(descriptor) {}
-  ~ScopedFileDescriptorCloser();
- private:
-  FileDescriptor* descriptor_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedFileDescriptorCloser);
-};
-
 }  // namespace chromeos_update_engine
 
 #endif  // UPDATE_ENGINE_FILE_DESCRIPTOR_H_