Add support for single sample metrics.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 5e96c377b69ea07b137319348aed0f16b59670f4..bb6fea39f062c71037f64ab6e3049ebcc10d7102 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -108,6 +108,7 @@
 #include "content/browser/renderer_host/media/video_capture_host.h"
 #include "content/browser/renderer_host/offscreen_canvas_compositor_frame_sink_provider_impl.h"
 #include "content/browser/renderer_host/offscreen_canvas_surface_factory_impl.h"
+#include "content/browser/renderer_host/one_shot_metric_host.h"
 #include "content/browser/renderer_host/pepper/pepper_message_filter.h"
 #include "content/browser/renderer_host/pepper/pepper_renderer_connection.h"
 #include "content/browser/renderer_host/render_message_filter.h"
@@ -1315,6 +1316,8 @@ void RenderProcessHostImpl::RegisterMojoInterfaces() {
       base::Bind(&VideoCaptureHost::Create,
                  BrowserMainLoop::GetInstance()->media_stream_manager()));
 
+  registry->AddInterface(base::Bind(&OneShotMetricHost::Create));
+
   // This is to support usage of WebSockets in cases in which there is no
   // associated RenderFrame (e.g., Shared Workers).
   AddUIThreadInterface(