Adding UMA on page load size for pages with Media

chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc

Index: chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc
diff --git a/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc b/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc
index 3de5193c61dad2d2b41ba10c1618fdb61e77911f..c74e1b8e54cb7b58a5c70abd5f581f74a8f8b420 100644
--- a/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc
+++ b/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc
@@ -14,6 +14,7 @@
 #include "chrome/common/page_load_metrics/page_load_metrics_messages.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "content/public/test/web_contents_tester.h"
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 
@@ -152,6 +153,14 @@ void PageLoadMetricsObserverTestHarness::SimulateAppEnterBackground() {
   observer_->FlushMetricsOnAppEnterBackground();
 }
 
+void PageLoadMetricsObserverTestHarness::SimulateMediaPlayed() {
+  content::WebContentsObserver::MediaPlayerInfo video_type(
+      true /* in_has_video*/);
+  content::RenderFrameHost* render_frame_host = web_contents()->GetMainFrame();
+  observer_->MediaStartedPlaying(video_type,
+                                 std::make_pair(render_frame_host, 0));
+}
+
 const base::HistogramTester&
 PageLoadMetricsObserverTestHarness::histogram_tester() const {
   return histogram_tester_;