Use TaskScheduler instead of blocking pool in version_handler_chromeos.cc.

chromeos/system/version_loader.h

Index: chromeos/system/version_loader.h
diff --git a/chromeos/system/version_loader.h b/chromeos/system/version_loader.h
index de6d2d73dedddce66cf34cd288a348f6286125dc..db1b80efdf58cd42bb8124189feb7f3f700d859b 100644
--- a/chromeos/system/version_loader.h
+++ b/chromeos/system/version_loader.h
@@ -21,15 +21,15 @@ enum VersionFormat {
 // Gets the version.
 // If |full_version| is true version string with extra info is extracted,
 // otherwise it's in short format x.x.xx.x.
-// Must be run on a blocking thread pool.
+// May block.
 CHROMEOS_EXPORT std::string GetVersion(VersionFormat format);
 
 // Gets the ARC version.
-// Must be run on a blocking thread pool.
+// May block.
 CHROMEOS_EXPORT std::string GetARCVersion();
 
 // Gets the firmware info.
-// Must be run on a blocking thread pool.
+// May block.
 CHROMEOS_EXPORT std::string GetFirmware();
 
 // Extracts the firmware from the file.