Add a new gyp flag: fieldtrial_testing_like_official_build

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index d80d4e405e7125cde7d6608bc80c32e8a0b99053..8b89807dd0807a63a52dc167776526928f62b574 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -149,6 +149,13 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/strings/grit/app_locale_settings.h"
 
+#if OFFICIAL_BUILD

[Alexei Svitkine (slow), 2015/08/03 18:23:10]

You switched from GOOGLE_CHROME_BUILD to OFFICIAL_BUILD. I thought
GOOGLE_CHROME_BUILD is the better thing to use? I think OFFICIAL_BUILD is what
just triggers extra optimizations when building Release? e.g. things like LTO

[danduong, 2015/08/03 18:30:59]

I was basically copying the convention from tracing_like_official build. It's
really not clear to me which is better and for which reason.

Is there any problem with this does? I believe the desire is to have the final
build NOT do field trial testing and all other builds to have it.

+#undef FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD
+#define FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD 1
+#elif !defined(FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD)
+#define FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD 0
+#endif

[Alexei Svitkine (slow), 2015/08/03 18:23:10]

Hmm, this is a bit messy to put at the top of this cc file. Maybe we could tuck
it away in a header file somewhere? Or in gyp/gn itself?

[danduong, 2015/08/03 20:52:49]

Moved it into gyp/gn

+
 #if defined(OS_ANDROID)
 #include "chrome/browser/android/dev_tools_discovery_provider_android.h"
 #include "chrome/browser/metrics/thread_watcher_android.h"
@@ -635,12 +642,12 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
                   << " list specified.";
   }
 
-#if !defined(GOOGLE_CHROME_BUILD)
+#if !FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD
   if (!command_line->HasSwitch(switches::kDisableFieldTrialTestingConfig) &&
       !command_line->HasSwitch(switches::kForceFieldTrials) &&
       !command_line->HasSwitch(switches::kVariationsServerURL))
     chrome_variations::AssociateDefaultFieldTrialConfig();
-#endif  // !defined(GOOGLE_CHROME_BUILD)
+#endif  // !FIELDTRIAL_TESTING_IS_OFFICIAL_BUILD
 
   if (command_line->HasSwitch(switches::kForceVariationIds)) {
     // Create default variation ids which will always be included in the