Decouple Metrics Initialization from IO Thread Initialization

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index c07681a7c35e2dcb7402cf75a08bebd8b1bbbb20..bf5ccdc226a6328d3152b355141d2c91f49c711f 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -1068,6 +1068,10 @@ void BrowserProcessImpl::PreMainMessageLoopRun() {
   SCOPED_UMA_HISTOGRAM_TIMER(
       "Startup.BrowserProcessImpl_PreMainMessageLoopRunTime");
 
+  // At this stage of startup, metrics should be good to go and we can
+  // initialize the metrics data use forwarder on the IO thread state object.
+  io_thread()->InitMetricsDataUseForwarder();
+
   // browser_policy_connector() is created very early because local_state()
   // needs policy to be initialized with the managed preference values.
   // However, policy fetches from the network and loading of disk caches