Avoid unnecessary registry/plist reads (hundreds of them) by caching the brand code.

chrome/browser/search_engines/ui_thread_search_terms_data.cc

Index: chrome/browser/search_engines/ui_thread_search_terms_data.cc
diff --git a/chrome/browser/search_engines/ui_thread_search_terms_data.cc b/chrome/browser/search_engines/ui_thread_search_terms_data.cc
index 9a31685b52640c5fe56e2d0085624b76c859eb37..6c0c3ba85d2748b11f483bb2d1cfb9bb0abdd761 100644
--- a/chrome/browser/search_engines/ui_thread_search_terms_data.cc
+++ b/chrome/browser/search_engines/ui_thread_search_terms_data.cc
@@ -76,11 +76,15 @@ base::string16 UIThreadSearchTermsData::GetRlzParameterValue(
       BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::string16 rlz_string;
 #if BUILDFLAG(ENABLE_RLZ)
+  static std::string* brand = []() {
+    auto extracted = new std::string();

[Lei Zhang, 2017/05/18 01:52:50]

This broke official builds. It needs to be auto*.

+    if (!google_brand::GetBrand(extracted))
+      extracted->clear();
+    return extracted;
+  }();
   // For organic brandcodes do not use rlz at all. Empty brandcode usually
   // means a chromium install. This is ok.
-  std::string brand;
-  if (google_brand::GetBrand(&brand) && !brand.empty() &&
-      !google_brand::IsOrganic(brand)) {
+  if (!brand->empty() && !google_brand::IsOrganic(*brand)) {
     // This call will return false the first time(s) it is called until the
     // value has been cached. This normally would mean that at most one omnibox
     // search might not send the RLZ data but this is not really a problem.