[Metrics] Make MetricsStateManager take a callback param to check if UMA is enabled.

chrome/browser/metrics/metrics_services_manager.cc

Index: chrome/browser/metrics/metrics_services_manager.cc
diff --git a/chrome/browser/metrics/metrics_services_manager.cc b/chrome/browser/metrics/metrics_services_manager.cc
index 002f18383235aebe6ef0c5202704345f570b54c1..acbbb7542ab2e4e9053b6330e6b6f27a23c17488 100644
--- a/chrome/browser/metrics/metrics_services_manager.cc
+++ b/chrome/browser/metrics/metrics_services_manager.cc
@@ -4,11 +4,44 @@
 
 #include "chrome/browser/metrics/metrics_services_manager.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/metrics/metrics_service.h"
 #include "chrome/browser/metrics/metrics_state_manager.h"
 #include "chrome/browser/metrics/variations/variations_service.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/pref_names.h"
 #include "components/rappor/rappor_service.h"
 
+namespace {
+
+// TODO(asvitkine): This function does not report the correct value on Android,
+// see http://crbug.com/362192.
+bool IsMetricsReportingEnabled() {
+  // If the user permits metrics reporting with the checkbox in the
+  // prefs, we turn on recording.  We disable metrics completely for
+  // non-official builds.  This can be forced with a flag.
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kEnableMetricsReportingForTesting))
+    return true;
+
+  // Disable metrics reporting when field trials are forced.
+  if (command_line->HasSwitch(switches::kForceFieldTrials))
+    return false;
+
+  bool enabled = false;
+#if defined(GOOGLE_CHROME_BUILD)
+#if defined(OS_CHROMEOS)
+  chromeos::CrosSettings::Get()->GetBoolean(chromeos::kStatsReportingPref,
+                                            &enabled);
+#else
+  enabled = local_state_->GetBoolean(prefs::kMetricsReportingEnabled);
+#endif  // #if defined(OS_CHROMEOS)
+#endif  // defined(GOOGLE_CHROME_BUILD)
+  return enabled;
+}
+
+}  // namespace
+
 MetricsServicesManager::MetricsServicesManager(PrefService* local_state)
     : local_state_(local_state) {
   DCHECK(local_state);
@@ -44,7 +77,9 @@ MetricsServicesManager::GetVariationsService() {
 
 metrics::MetricsStateManager* MetricsServicesManager::GetMetricsStateManager() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  if (!metrics_state_manager_)
-    metrics_state_manager_ = metrics::MetricsStateManager::Create(local_state_);
+  if (!metrics_state_manager_) {
+    metrics_state_manager_ = metrics::MetricsStateManager::Create(
+        local_state_, base::Bind(&IsMetricsReportingEnabled));
+  }
   return metrics_state_manager_.get();
 }