Reland "Prepare blink to unify definitions of load completion"

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index 640d69af701d16bc320672cf21b3a4f62ee28c19..b6c52217cb875f443743e8ae15553dea177614ee 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -243,8 +243,10 @@ bool FrameLoader::closeURL()
 void FrameLoader::didExplicitOpen()
 {
     // Calling document.open counts as committing the first real document load.
-    if (!m_stateMachine.committedFirstRealDocumentLoad())
+    if (!m_stateMachine.committedFirstRealDocumentLoad()) {
         m_stateMachine.advanceTo(FrameLoaderStateMachine::CommittedFirstRealLoad);
+        m_progressTracker->progressStarted();
+    }
 
     // Prevent window.open(url) -- eg window.open("about:blank") -- from blowing away results
     // from a subsequent window.document.open / window.document.write call.
@@ -958,6 +960,7 @@ FrameLoadType FrameLoader::loadType() const
     return m_loadType;
 }
 
+#if defined(ENABLE_LOAD_COMPLETION_HACKS)
 // This function is an incomprehensible mess and is only used in checkLoadCompleteForThisFrame.
 // If you're thinking of using it elsewhere, stop right now and reconsider your life.
 static bool isDocumentDoneLoading(Document* document)
@@ -966,10 +969,8 @@ static bool isDocumentDoneLoading(Document* document)
         return true;
     if (document->loader()->isLoadingMainResource())
         return false;
-    if (!document->loadEventFinished()) {
-        if (document->loader()->isLoading() || document->isDelayingLoadEvent())
-            return false;
-    }
+    if (!document->loadEventFinished())
+        return false;
     if (document->fetcher()->requestCount())
         return false;
     if (document->processingLoadEvent())
@@ -978,6 +979,7 @@ static bool isDocumentDoneLoading(Document* document)
         return false;
     return true;
 }
+#endif
 
 bool FrameLoader::checkLoadCompleteForThisFrame()
 {
@@ -1013,8 +1015,16 @@ bool FrameLoader::checkLoadCompleteForThisFrame()
         return true;
     if (m_provisionalDocumentLoader || !m_documentLoader)
         return false;
+
+#if defined(ENABLE_LOAD_COMPLETION_HACKS)
     if (!isDocumentDoneLoading(m_frame->document()) && !m_inStopAllLoaders)
         return false;
+#else
+    if (m_inStopAllLoaders)
+        m_frame->document()->suppressLoadEvent();
+    if (!m_frame->document()->loadEventFinished())
+        return false;
+#endif
 
     m_state = FrameStateComplete;
 
@@ -1273,6 +1283,8 @@ void FrameLoader::loadWithNavigationAction(const NavigationAction& action, Frame
     if ((!m_policyDocumentLoader->shouldContinueForNavigationPolicy(request, shouldCheckMainWorldContentSecurityPolicy, isTransitionNavigation) || !shouldClose()) && m_policyDocumentLoader) {
         m_policyDocumentLoader->detachFromFrame();
         m_policyDocumentLoader = nullptr;
+        if (!m_stateMachine.committedFirstRealDocumentLoad())
+            m_state = FrameStateComplete;
         checkCompleted();
         return;
     }