Adding local field trial for metrics/crash reports sampling.

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 a0600754d5bbddbcdfdc38ae6995e5e3e9248ee4..dfcd7152f92c3c8357a5d7c925f9103eb0049924 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -907,8 +907,13 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
 
   variations::VariationsService* variations_service =
       browser_process_->variations_service();
-  if (variations_service)
-    variations_service->CreateTrialsFromSeed(feature_list.get());
+  bool has_seed = false;

[Lei Zhang, 2016/08/30 21:31:28]

How about:

bool has_seed = variations_service && variations_service->Foo();

and then "let git cl format" make it pretty?

[jwd, 2016/08/30 21:46:24]

Done.

+  if (variations_service) {
+    has_seed = variations_service->CreateTrialsFromSeed(feature_list.get());
+  }
+
+  browser_field_trials_.SetupFeatureControllingFieldTrials(has_seed,
+                                                           feature_list.get());
 
   base::FeatureList::SetInstance(std::move(feature_list));