Add braces to if statement in registration.cc

This makes no behavior change, since the if statement should only be
inserted if the `RegisterPnaclComponent` call has also been inserted.
However, it makes it clearer that there is no bug related to the missing
bracket and an unintentionally un-inserted statement. I.e., a bug of the
form:

if (condition)
# if SOME_FLAG
  conditional_stmt();
# endif

unconditional_stmt();

Note that in the above snippet, if SOME_FLAG is false, then
`unconditional_stmt` will unintentionally become conditional.

Again, the current code does not exhibit this bug, but at a quick
glance, that is not obvious.

Change-Id: Ibb41d390ae5be698421266ad494ea03dcb95532f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2617462Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Chris Fredrickson <cfredric@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841545}

chrome/browser/component_updater/registration.cc

@@ -105,9 +105,12 @@ void RegisterComponentsForUpdate(bool is_off_the_record_profile,
   // PNaCl on Chrome OS is on rootfs and there is no need to download it. But
   // Chrome4ChromeOS on Linux doesn't contain PNaCl so enable component
   // installer when running on Linux. See crbug.com/422121 for more details.
-  if (!base::SysInfo::IsRunningOnChromeOS())
+  if (!base::SysInfo::IsRunningOnChromeOS()) {
 #endif  // BUILDFLAG(IS_CHROMEOS_ASH)
     RegisterPnaclComponent(cus);
+#if BUILDFLAG(IS_CHROMEOS_ASH)
+  }
+#endif  // BUILDFLAG(IS_CHROMEOS_ASH)
 #endif  // BUILDFLAG(ENABLE_NACL) && !defined(OS_ANDROID)
 
   RegisterSubresourceFilterComponent(cus);