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

third_party/WebKit/Source/core/loader/SinkDocument.h

Index: third_party/WebKit/Source/core/loader/SinkDocument.h
diff --git a/third_party/WebKit/Source/core/loader/SinkDocument.h b/third_party/WebKit/Source/core/loader/SinkDocument.h
index 8a2ceb4b4e8e0e4625ad0b1445e5370c595e32a3..84bafa902625b59fbc06d0740c5a6b87a115b1e4 100644
--- a/third_party/WebKit/Source/core/loader/SinkDocument.h
+++ b/third_party/WebKit/Source/core/loader/SinkDocument.h
@@ -41,6 +41,8 @@ private:
     SinkDocument(const DocumentInit&);
 
     PassRefPtrWillBeRawPtr<DocumentParser> createParser() override;
+
+    String debugName() const override { return "SinkDocument"; }
 };