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

chrome/browser/search_engines/ui_thread_search_terms_data.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/search_engines/ui_thread_search_terms_data.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "build/build_config.h"
@@ skipping 58 matching lines @@
 }
 
 // Android implementations are in ui_thread_search_terms_data_android.cc.
 #if !defined(OS_ANDROID)
 base::string16 UIThreadSearchTermsData::GetRlzParameterValue(
     bool from_app_list) const {
   DCHECK(!BrowserThread::IsThreadInitialized(BrowserThread::UI) ||
       BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::string16 rlz_string;
 #if BUILDFLAG(ENABLE_RLZ)
+  static std::string* brand = NULL;

[grt (UTC plus 2), 2017/05/17 08:45:43]

the idiomatic way i've seen to do this sort of one-time initialization is:
  static std::string* brand = []() {
    auto brand = new std::string();
    if (!google_brand::GetBrand(brand))
      brand->clear();
    return brand;
  }();

[Boris Vidolov, 2017/05/17 18:37:10]

Sure. I've seen both and I just used the old-fashioned way (as here:
https://cs.chromium.org/chromium/src/url/gurl.cc?rcl=733abfce87eb65cf777c6c12...)

Changed now. Technically, I don't need to clear on failure based on the current
implementation of google_brand::GetBrand, but given that this is now a one-time
call, I will throw it there.

+  if (!brand) {
+    brand = new std::string();
+    google_brand::GetBrand(brand);
+  }
   // 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.
     rlz_lib::AccessPoint access_point = rlz::RLZTracker::ChromeOmnibox();
     if (from_app_list)
       access_point = rlz::RLZTracker::ChromeAppList();
     rlz::RLZTracker::GetAccessPointRlz(access_point, &rlz_string);
   }
 #endif
   return rlz_string;
@@ skipping 52 matching lines @@
   if (!modifier.empty())
     version += " " + modifier;
   return version;
 }
 
 // static
 void UIThreadSearchTermsData::SetGoogleBaseURL(const std::string& base_url) {
   delete google_base_url_;
   google_base_url_ = base_url.empty() ? NULL : new std::string(base_url);
 }