NOT FOR LANDING Implement WebMediaSession

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index c4a009dc7ab3ff296833d3ed099402d86a7bbe44..0a650caf90147bb3ebc4a30b815653e8f1ab5d99 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -54,6 +54,7 @@
 #include "content/renderer/gamepad_shared_memory_reader.h"
 #include "content/renderer/media/audio_decoder.h"
 #include "content/renderer/media/renderer_webaudiodevice_impl.h"
+#include "content/renderer/media/renderer_webmediasession_impl.h"
 #include "content/renderer/media/renderer_webmidiaccessor_impl.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/renderer_clipboard_delegate.h"
@@ -338,6 +339,10 @@ void RendererBlinkPlatformImpl::createMessageChannel(
       default_task_runner_, channel1, channel2);
 }
 
+blink::WebMediaSession* RendererBlinkPlatformImpl::createMediaSession() {
+  return new RendererWebMediaSessionImpl();
+}
+
 blink::WebPrescientNetworking*
 RendererBlinkPlatformImpl::prescientNetworking() {
   return GetContentClient()->renderer()->GetPrescientNetworking();