tracing: Report ResourceClients and the reason for not deletable for web-caches

third_party/WebKit/Source/core/html/MediaDocument.h

Index: third_party/WebKit/Source/core/html/MediaDocument.h
diff --git a/third_party/WebKit/Source/core/html/MediaDocument.h b/third_party/WebKit/Source/core/html/MediaDocument.h
index bfd0fb278b63adc308d7aef6b305c120d48f6848..f762c52063f25b2021d5a0f76875b2d4abef52a7 100644
--- a/third_party/WebKit/Source/core/html/MediaDocument.h
+++ b/third_party/WebKit/Source/core/html/MediaDocument.h
@@ -43,6 +43,8 @@ private:
     PassRefPtrWillBeRawPtr<DocumentParser> createParser() override;
 
     void defaultEventHandler(Event*) override;
+
+    String debugName() const override { return "MediaDocument"; }
 };
 
 }