Fuchsia: Prepare for OS_POSIX removal in storage/

This cleans up multi-platform code paths selection and prepares for
the removal of OS_POSIX for the Fuchsia build.

Bug: 836416
Change-Id: I45af4ff9525a3129c077101ad4e365c79490299e
Reviewed-on: https://chromium-review.googlesource.com/1033969
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556950}

storage/browser/database/vfs_backend.cc

@@ -126,7 +126,7 @@ int VfsBackend::DeleteFile(const base::FilePath& file_path, bool sync_dir) {
     return SQLITE_IOERR_DELETE;
 
   int error_code = SQLITE_OK;
-#if defined(OS_POSIX)
+#if defined(OS_POSIX) || defined(OS_FUCHSIA)
   if (sync_dir) {
     base::File dir(file_path.DirName(), base::File::FLAG_READ);
     if (dir.IsValid()) {
@@ -144,7 +144,7 @@ int VfsBackend::DeleteFile(const base::FilePath& file_path, bool sync_dir) {
 uint32_t VfsBackend::GetFileAttributes(const base::FilePath& file_path) {
 #if defined(OS_WIN)
   uint32_t attributes = ::GetFileAttributes(file_path.value().c_str());
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
   uint32_t attributes = 0;
   if (!access(file_path.value().c_str(), R_OK))
     attributes |= static_cast<uint32_t>(R_OK);

storage/common/fileapi/file_system_util.cc

@@ -13,6 +13,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
 #include "net/base/escape.h"
 #include "net/base/net_errors.h"
 #include "storage/common/database/database_identifier.h"
@@ -324,15 +325,15 @@ std::string GetFileSystemTypeString(FileSystemType type) {
 std::string FilePathToString(const base::FilePath& file_path) {
 #if defined(OS_WIN)
   return base::UTF16ToUTF8(file_path.value());
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
   return file_path.value();
 #endif
 }
 
 base::FilePath StringToFilePath(const std::string& file_path_string) {
 #if defined(OS_WIN)
   return base::FilePath(base::UTF8ToUTF16(file_path_string));
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
   return base::FilePath(file_path_string);
 #endif
 }