[base] Fix SysInfoWin for base::string16 switch

This change prepapres sys_info_win for the string of base::string16 to
std::u16string.

Bug: 911896
Change-Id: I53c2cb2127aa576d8c4f83382893c5ffdd095070
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2642267
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845619}

base/system/sys_info_win.cc

@@ -169,7 +169,7 @@ void SysInfo::OperatingSystemVersionNumbers(int32_t* major_version,
 
 // static
 SysInfo::HardwareInfo SysInfo::GetHardwareInfoSync() {
-  constexpr base::char16 kSystemBiosInformationRegKey[] =
+  constexpr wchar_t kSystemBiosInformationRegKey[] =
       L"HARDWARE\\DESCRIPTION\\System\\BIOS";
 
   HardwareInfo info;
@@ -177,15 +177,15 @@ SysInfo::HardwareInfo SysInfo::GetHardwareInfoSync() {
   if (system_information_key.Open(HKEY_LOCAL_MACHINE,
                                   kSystemBiosInformationRegKey,
                                   KEY_READ) == ERROR_SUCCESS) {
-    base::string16 value16;
-    if (system_information_key.ReadValue(L"SystemManufacturer", &value16) ==
+    std::wstring value;
+    if (system_information_key.ReadValue(L"SystemManufacturer", &value) ==
         ERROR_SUCCESS) {
-      info.manufacturer = base::SysWideToUTF8(value16);
+      info.manufacturer = base::SysWideToUTF8(value);
     }
 
-    if (system_information_key.ReadValue(L"SystemProductName", &value16) ==
+    if (system_information_key.ReadValue(L"SystemProductName", &value) ==
         ERROR_SUCCESS) {
-      info.model = base::SysWideToUTF8(value16);
+      info.model = base::SysWideToUTF8(value);
     }
   }