[Fetch, Loader] Expect on-heap objects will never get destroyed with a reference

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 83912c85c72ef76136a71665479b9a957ef579fc..4be0fd7fbd413dd8abf6baaf37112ca3c0200590 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -354,9 +354,6 @@ void FrameLoader::replaceDocumentWhileExecutingJavaScriptURL(
           Document::NoDismissal)
     return;
 
-  // DocumentLoader::replaceDocumentWhileExecutingJavaScriptURL can cause the
-  // DocumentLoader to get deref'ed and possible destroyed, so protect it with a
-  // RefPtr.
   DocumentLoader* documentLoader(m_frame->document()->loader());
 
   UseCounter::count(*m_frame->document(),
@@ -613,7 +610,7 @@ void FrameLoader::finishedParsing() {
   checkCompleted();
 
   if (!m_frame->view())
-    return;  // We are being destroyed by something checkCompleted called.

[hiroshige, 2016/10/21 05:45:14]

If this |if| block remains, then should we leave some comments that mentions
this condition holds due to something checkCompleted called (if not destroyed
though)?

[yhirano, 2016/10/26 11:09:34]

I'm not 100% sure but it looks FrameLoaderClient::runScriptsAtDocumentReady may
invalidate the frame, too. Regardless of the reason, we shouldn't run L620 if
m_frame->view() is null.

https://cs.chromium.org/chromium/src/content/public/renderer/content_renderer...

+    return;
 
   // Check if the scrollbars are really needed for the content. If not, remove
   // them, relayout, and repaint.