Send the value of google_brand::GetBrand in component update checks.

components/update_client/utils.cc

Index: components/update_client/utils.cc
diff --git a/components/update_client/utils.cc b/components/update_client/utils.cc
index a6ec277e6e9708eee70cc64c8b8afed32620be43..a76e07329fac74a7c32c71d97fdb4edfd8fe4e9a 100644
--- a/components/update_client/utils.cc
+++ b/components/update_client/utils.cc
@@ -6,6 +6,8 @@
 
 #include <stddef.h>
 #include <stdint.h>
+
+#include <algorithm>
 #include <cmath>
 #include <cstring>
 #include <vector>
@@ -226,4 +228,14 @@ bool VerifyFileHash256(const base::FilePath& filepath,
   return memcmp(actual_hash, &expected_hash[0], sizeof(actual_hash)) == 0;
 }
 
+bool IsValidBrand(const std::string& brand) {
+  const size_t kMaxBrandSize = 4;
+  if (brand.size() > kMaxBrandSize)
+    return false;
+
+  return std::find_if_not(brand.begin(), brand.end(), [](char ch) {
+           return base::IsAsciiAlpha(ch);
+         }) == brand.end();
+}
+
 }  // namespace update_client