Always send a fail or finish notification for each navigation.

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

Index: third_party/WebKit/Source/core/loader/DocumentLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
index cd0ad37635b8179069d1bfc7e22ee43e7f2f4497..9e7d9aab88292d096812dacfe2d77a67a7e6974c 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
@@ -131,6 +131,7 @@ DocumentLoader::~DocumentLoader() {
   DCHECK(!m_frame);
   DCHECK(!m_mainResource);
   DCHECK(!m_applicationCacheHost);
+  DCHECK_EQ(m_state, SentDidFinishLoad);
 }
 
 DEFINE_TRACE(DocumentLoader) {
@@ -280,7 +281,6 @@ void DocumentLoader::notifyFinished(Resource* resource) {
 
   if (m_applicationCacheHost)
     m_applicationCacheHost->failedLoadingMainResource();
-  m_state = MainResourceDone;
   frameLoader()->loadFailed(this, m_mainResource->resourceError());
   clearMainResourceHandle();
 }
@@ -314,8 +314,6 @@ void DocumentLoader::finishedLoading(double finishTime) {
 
   m_applicationCacheHost->finishedLoadingMainResource();
   endWriting();
-  if (m_state < MainResourceDone)
-    m_state = MainResourceDone;
   clearMainResourceHandle();
 }
 
@@ -550,7 +548,7 @@ void DocumentLoader::ensureWriter(const AtomicString& mimeType,
 }
 
 void DocumentLoader::commitData(const char* bytes, size_t length) {
-  DCHECK_LT(m_state, MainResourceDone);
+  DCHECK_EQ(m_state, Committed);
   ensureWriter(m_response.mimeType());
 
   // This can happen if document.close() is called by an event handler while
@@ -632,6 +630,9 @@ void DocumentLoader::detachFromFrame() {
   // frame have any loads active, so go ahead and kill all the loads.
   m_fetcher->stopFetching();
 
+  if (frameLoader() && !sentDidFinishLoad())
+    frameLoader()->loadFailed(this, ResourceError::cancelledError(url()));

[Nate Chapin, 2016/12/12 21:40:37]

This feels a little hacky, but it ensures we always send a didFail(). I don't
see a great alternative to it.

[gsennton, 2016/12/13 13:59:55]

I'm not sure I understand when we should receive a didFinishLoad and when we
should receive a didFailLoad.
Today we receive didFinishLoad for loads where the request fails but we do
receive some content from the server (and here you suggest posting didFailLoad
if the request fails but the response contains no data?). OnPageFinished is only
posted if we receive didFinishLoad (and in some specific cases of didFailLoad -
namely if we end up with the error NetError.ERR_ABORTED).

Should the behaviour between failing requests with, and without content (we
still receive a response, it just contains no data) from the server actually
differ?

+
   // If that load cancellation triggered another detach, leave.
   // (fast/frames/detach-frame-nested-no-crash.html is an example of this.)
   if (!m_frame)