Abort ImportantFileWriter::WriteFileAtomically() on Flush() error.

base/files/important_file_writer.cc

Index: base/files/important_file_writer.cc
diff --git a/base/files/important_file_writer.cc b/base/files/important_file_writer.cc
index c996da23a1501f2fbe2f18af2e1e585ea9153aed..d7579abb112432f8e97be4a81d5c6b1ea1c484ba 100644
--- a/base/files/important_file_writer.cc
+++ b/base/files/important_file_writer.cc
@@ -33,6 +33,7 @@ enum TempFileFailure {
   FAILED_CLOSING,
   FAILED_WRITING,
   FAILED_RENAMING,
+  FAILED_FLUSHING,
   TEMP_FILE_FAILURE_MAX
 };
 
@@ -69,7 +70,7 @@ bool ImportantFileWriter::WriteFileAtomically(const FilePath& path,
   CHECK_LE(data.length(), static_cast<size_t>(kint32max));
   int bytes_written = tmp_file.Write(0, data.data(),
                                      static_cast<int>(data.length()));
-  tmp_file.Flush();  // Ignore return value.
+  bool flush_success = tmp_file.Flush();
   tmp_file.Close();
 
   if (bytes_written < static_cast<int>(data.length())) {
@@ -79,6 +80,12 @@ bool ImportantFileWriter::WriteFileAtomically(const FilePath& path,
     return false;
   }
 
+  if (!flush_success) {
+    LogFailure(path, FAILED_FLUSHING, "error flushing");
+    base::DeleteFile(tmp_file_path, false);
+    return false;
+  }
+
   if (!base::ReplaceFile(tmp_file_path, path, NULL)) {
     LogFailure(path, FAILED_RENAMING, "could not rename temporary file");
     base::DeleteFile(tmp_file_path, false);