Add support for single sample metrics.

content/browser/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
 import("//third_party/WebKit/public/public_features.gni")
@@ skipping 1139 matching lines @@
     "renderer_host/offscreen_canvas_compositor_frame_sink.cc",
     "renderer_host/offscreen_canvas_compositor_frame_sink.h",
     "renderer_host/offscreen_canvas_compositor_frame_sink_provider_impl.cc",
     "renderer_host/offscreen_canvas_compositor_frame_sink_provider_impl.h",
     "renderer_host/offscreen_canvas_surface_factory_impl.cc",
     "renderer_host/offscreen_canvas_surface_factory_impl.h",
     "renderer_host/offscreen_canvas_surface_impl.cc",
     "renderer_host/offscreen_canvas_surface_impl.h",
     "renderer_host/offscreen_canvas_surface_manager.cc",
     "renderer_host/offscreen_canvas_surface_manager.h",
+    "renderer_host/one_shot_metric_host.cc",
+    "renderer_host/one_shot_metric_host.h",
     "renderer_host/overscroll_configuration.cc",
     "renderer_host/overscroll_controller.cc",
     "renderer_host/overscroll_controller.h",
     "renderer_host/overscroll_controller_delegate.h",
     "renderer_host/render_message_filter.cc",
     "renderer_host/render_message_filter.h",
     "renderer_host/render_process_host_impl.cc",
     "renderer_host/render_process_host_impl.h",
     "renderer_host/render_sandbox_host_linux.cc",
     "renderer_host/render_sandbox_host_linux.h",
@@ skipping 845 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }