Wrap MediaMetadata in base::Optional in content and chrome

content/renderer/media/android/renderer_media_session_manager.cc

Index: content/renderer/media/android/renderer_media_session_manager.cc
diff --git a/content/renderer/media/android/renderer_media_session_manager.cc b/content/renderer/media/android/renderer_media_session_manager.cc
index da956eced8f2b9f819e53f15287e3ae5ee6b5c55..1691cddc52c5f9020bac213558367dfc000ff8ab 100644
--- a/content/renderer/media/android/renderer_media_session_manager.cc
+++ b/content/renderer/media/android/renderer_media_session_manager.cc
@@ -64,15 +64,15 @@ void RendererMediaSessionManager::Deactivate(
 }
 
 void RendererMediaSessionManager::SetMetadata(
-    int session_id,
-    const MediaMetadata& metadata) {
+    int session_id, const base::Optional<MediaMetadata>& metadata) {
 
   // TODO(zqzhang): print a console warning when metadata is dirty. See
   // https://crbug.com/625244.
   Send(new MediaSessionHostMsg_SetMetadata(
       routing_id(), session_id,
-      MediaMetadataSanitizer::CheckSanity(metadata) ?
-      metadata : MediaMetadataSanitizer::Sanitize(metadata)));
+      (!metadata || MediaMetadataSanitizer::CheckSanity(metadata.value()))

[mlamouri (slow - plz ping), 2016/09/01 17:47:49]

Maybe `!metadata.has_value()` instead of `!metadata`?

[Zhiqiang Zhang (Slow), 2016/09/02 12:11:41]

Done.

+      ? metadata
+      : MediaMetadataSanitizer::Sanitize(metadata.value())));
 }
 
 void RendererMediaSessionManager::OnDidActivate(int request_id, bool success) {