Remove OnRecordingDisabled() metrics client interface.

blimp/engine/app/blimp_metrics_service_client.cc

Index: blimp/engine/app/blimp_metrics_service_client.cc
diff --git a/blimp/engine/app/blimp_metrics_service_client.cc b/blimp/engine/app/blimp_metrics_service_client.cc
index 6149b5a333eab772900fc8cf32679a358101c0fe..5b25f9349fbaa2c467c459319865ffb06099c0fb 100644
--- a/blimp/engine/app/blimp_metrics_service_client.cc
+++ b/blimp/engine/app/blimp_metrics_service_client.cc
@@ -90,13 +90,10 @@ metrics::MetricsService* BlimpMetricsServiceClient::GetMetricsService() {
 
 // In Chrome, UMA and Breakpad are enabled/disabled together by the same
 // checkbox and they share the same client ID (a.k.a. GUID).
-// This is not required by Blimp, so these are no-ops.
+// This is not required by Blimp, so this is a no-op.
 void BlimpMetricsServiceClient::SetMetricsClientId(
     const std::string& client_id) {}
 
-// Recording can not be disabled in Blimp, so this function is a no-op.
-void BlimpMetricsServiceClient::OnRecordingDisabled() {}
-
 bool BlimpMetricsServiceClient::IsOffTheRecordSessionActive() {
   // Blimp does not have incognito mode.
   return false;