win: Add open equivalent

util/file/file_writer_posix.cc

Index: util/file/file_writer_posix.cc
diff --git a/util/file/file_writer.cc b/util/file/file_writer_posix.cc
similarity index 79%
copy from util/file/file_writer.cc
copy to util/file/file_writer_posix.cc
index 4f833051122ecc6fc88ff9fc48473b8626e6158f..533f787b996a910ddaab165377cf93ab819bacb4 100644
--- a/util/file/file_writer.cc
+++ b/util/file/file_writer_posix.cc
@@ -20,7 +20,6 @@
 
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
-#include "util/file/file_io.h"
 
 namespace crashpad {
 
@@ -31,19 +30,13 @@ static_assert(offsetof(WritableIoVec, iov_base) == offsetof(iovec, iov_base),
 static_assert(offsetof(WritableIoVec, iov_len) == offsetof(iovec, iov_len),
               "WritableIoVec len offset");
 
-FileWriter::FileWriter() : fd_() {
-}
-
-FileWriter::~FileWriter() {
-}
-
-bool FileWriter::Open(const base::FilePath& path, int oflag, mode_t mode) {
-  CHECK(!fd_.is_valid());
+bool FileWriter::Open(const base::FilePath& path, int oflag, uint32_t mode) {
+  CHECK(!file.is_valid());
 
   DCHECK((oflag & O_WRONLY) || (oflag & O_RDWR));
 
-  fd_.reset(HANDLE_EINTR(open(path.value().c_str(), oflag, mode)));
-  if (!fd_.is_valid()) {
+  file.reset(HANDLE_EINTR(open(path.value().c_str(), oflag, mode)));
+  if (!file.is_valid()) {
     PLOG(ERROR) << "open " << path.value();
     return false;
   }
@@ -51,28 +44,6 @@ bool FileWriter::Open(const base::FilePath& path, int oflag, mode_t mode) {
   return true;
 }
 
-void FileWriter::Close() {
-  CHECK(fd_.is_valid());
-
-  fd_.reset();
-}
-
-bool FileWriter::Write(const void* data, size_t size) {
-  DCHECK(fd_.is_valid());
-
-  // TODO(mark): Write no more than SSIZE_MAX bytes in a single call.
-  ssize_t written = WriteFile(fd_.get(), data, size);
-  if (written < 0) {
-    PLOG(ERROR) << "write";
-    return false;
-  } else if (written == 0) {
-    LOG(ERROR) << "write: returned 0";
-    return false;
-  }
-
-  return true;
-}
-
 bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
   DCHECK(fd_.is_valid());
 
@@ -137,10 +108,10 @@ bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
   return true;
 }
 
-off_t FileWriter::Seek(off_t offset, int whence) {
-  DCHECK(fd_.is_valid());
+FileOffset FileWriter::Seek(FileOffset offset, int whence) {
+  DCHECK(file_.is_valid());
 
-  off_t rv = lseek(fd_.get(), offset, whence);
+  off_t rv = lseek(file_.get(), offset, whence);
   if (rv < 0) {
     PLOG(ERROR) << "lseek";
   }