Avoid unsafe forms for base::File::WriteAtCurrentPos()

Use the span based forms instead. Adjust callers to accommodate
an optional<size_t> return.

This CL was uploaded by git cl split.

R=jzw@chromium.org, khorimoto@chromium.org, skuhne@chromium.org, waffles@chromium.org, wtlee@chromium.org

Bug: 42271176
Change-Id: I7b1c5869e8660b017e036ce407c93b02a64c4878
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5819272
Reviewed-by: Wei Lee <wtlee@chromium.org>
Auto-Submit: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Stefan Kuhne <skuhne@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: John Wu <jzw@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1358864}

components/about_ui/credit_utils_android.cc

@@ -4,7 +4,7 @@
 
 #include "components/about_ui/credit_utils.h"
 
-#include "base/compiler_specific.h"
+#include "base/containers/span.h"
 #include "base/files/file.h"
 
 // Must come after all headers that specialize FromJniType() / ToJniType().
@@ -13,10 +13,8 @@
 namespace about_ui {
 
 static void JNI_CreditUtils_WriteCreditsHtml(JNIEnv* env, jint fd) {
-  std::string html_content = GetCredits(false);
   base::File out_file(fd);
-  UNSAFE_TODO(
-      out_file.WriteAtCurrentPos(html_content.c_str(), html_content.size()));
+  out_file.WriteAtCurrentPos(base::as_byte_span(GetCredits(false)));
 }
 
 }  // namespace about_ui

components/chromeos_camera/jpeg_encode_accelerator_unittest.cc

@@ -1,15 +1,19 @@
 // Copyright 2018 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
+
+#include "components/chromeos_camera/jpeg_encode_accelerator.h"
+
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-
 #include <sys/mman.h>
+
 #include <memory>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
+#include "base/containers/span.h"
 #include "base/files/file_util.h"
 #include "base/functional/bind.h"
 #include "base/logging.h"
@@ -27,7 +31,6 @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "components/chromeos_camera/gpu_jpeg_encode_accelerator_factory.h"
-#include "components/chromeos_camera/jpeg_encode_accelerator.h"
 #include "media/base/color_plane_layout.h"
 #include "media/base/test_data_util.h"
 #include "media/gpu/buildflags.h"
@@ -219,7 +222,7 @@ void JpegEncodeAcceleratorTestEnvironment::LogToFile(const std::string& key,
   std::string s = base::StringPrintf("%s: %s\n", key.c_str(), value.c_str());
   LOG(INFO) << s;
   if (log_file_) {
-    log_file_->WriteAtCurrentPos(s.data(), static_cast<int>(s.length()));
+    log_file_->WriteAtCurrentPos(base::as_byte_span(s));
   }
 }
 

components/language_detection/core/language_detection_model_unittest.cc

@@ -7,6 +7,7 @@
 #include <memory>
 
 #include "base/compiler_specific.h"
+#include "base/containers/span.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/metrics/metrics_hashes.h"
@@ -30,7 +31,8 @@ base::File CreateInvalidModelFile() {
   base::File file(file_path, (base::File::FLAG_CREATE | base::File::FLAG_READ |
                               base::File::FLAG_WRITE |
                               base::File::FLAG_CAN_DELETE_ON_CLOSE));
-  EXPECT_TRUE(UNSAFE_TODO(file.WriteAtCurrentPos("12345", 5)));
+  EXPECT_TRUE(
+      file.WriteAtCurrentPosAndCheck(base::byte_span_from_cstring("12345")));
   return file;
 }
 

components/sessions/core/command_storage_backend.cc

@@ -16,6 +16,7 @@
 #include <string_view>
 #include <utility>
 
+#include "base/containers/span.h"
 #include "base/feature_list.h"
 #include "base/features.h"
 #include "base/files/file.h"
@@ -766,8 +767,7 @@ std::unique_ptr<base::File> CommandStorageBackend::OpenAndWriteHeader(
   header.signature = kFileSignature;
   header.version =
       IsEncrypted() ? kEncryptedFileVersionWithMarker : kFileVersionWithMarker;
-  if (file->WriteAtCurrentPos(reinterpret_cast<char*>(&header),
-                              sizeof(header)) != sizeof(header)) {
+  if (!file->WriteAtCurrentPosAndCheck(base::byte_span_from_ref(header))) {
     return nullptr;
   }
   return file;
@@ -777,24 +777,22 @@ bool CommandStorageBackend::AppendCommandToFile(
     base::File* file,
     const sessions::SessionCommand& command) {
   const size_type total_size = command.GetSerializedSize();
-  if (file->WriteAtCurrentPos(reinterpret_cast<const char*>(&total_size),
-                              sizeof(total_size)) != sizeof(total_size)) {
+  if (!file->WriteAtCurrentPosAndCheck(base::byte_span_from_ref(total_size))) {
     DVLOG(1) << "error writing";
     return false;
   }
   id_type command_id = command.id();
-  if (file->WriteAtCurrentPos(reinterpret_cast<char*>(&command_id),
-                              sizeof(command_id)) != sizeof(command_id)) {
+  if (!file->WriteAtCurrentPosAndCheck(base::byte_span_from_ref(command_id))) {
     DVLOG(1) << "error writing";
     return false;
   }
-
   const size_type content_size = total_size - sizeof(id_type);
-  if (content_size == 0)
+  if (content_size == 0) {
     return true;
-
-  if (file->WriteAtCurrentPos(reinterpret_cast<const char*>(command.contents()),
-                              content_size) != content_size) {
+  }
+  if (!file->WriteAtCurrentPos(
+          base::as_byte_span(command.contents_as_string_piece())
+              .first(content_size))) {
     DVLOG(1) << "error writing";
     return false;
   }
@@ -835,15 +833,12 @@ bool CommandStorageBackend::AppendEncryptedCommandToFile(
   const size_type command_and_id_size =
       static_cast<size_type>(cipher_text.size());
 
-  int wrote = file->WriteAtCurrentPos(
-      reinterpret_cast<const char*>(&command_and_id_size),
-      sizeof(command_and_id_size));
-  if (wrote != sizeof(command_and_id_size)) {
+  if (!file->WriteAtCurrentPosAndCheck(
+          base::byte_span_from_ref(command_and_id_size))) {
     DVLOG(1) << "error writing";
     return false;
   }
-  wrote = file->WriteAtCurrentPos(cipher_text.c_str(), cipher_text.size());
-  if (wrote != static_cast<int>(cipher_text.size())) {
+  if (!file->WriteAtCurrentPosAndCheck(base::as_byte_span(cipher_text))) {
     DVLOG(1) << "error writing";
     return false;
   }

components/winhttp/network_fetcher.cc

@@ -14,7 +14,7 @@
 
 #include "base/check.h"
 #include "base/check_op.h"
-#include "base/compiler_specific.h"
+#include "base/containers/span.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/functional/bind.h"
@@ -455,8 +455,7 @@ bool NetworkFetcher::WriteDataToFileBlocking() {
     }
   }
 
-  if (UNSAFE_TODO(file_.WriteAtCurrentPos(&read_buffer_.front(),
-                                          read_buffer_.size())) == -1) {
+  if (!file_.WriteAtCurrentPosAndCheck(base::as_byte_span(read_buffer_))) {
     net_error_ = HRESULTFromLastError();
     file_.Close();
     base::DeleteFile(file_path_);