Reland "Move most of FrameLoader::CheckCompleted() to Document"

third_party/WebKit/Source/web/WebFrame.cpp

Index: third_party/WebKit/Source/web/WebFrame.cpp
diff --git a/third_party/WebKit/Source/web/WebFrame.cpp b/third_party/WebKit/Source/web/WebFrame.cpp
index 29bf0d8c04e50f829b0c326208c3b21c650beb84..25467b57a4d9ee659e0f79b8df04209c77329e30 100644
--- a/third_party/WebKit/Source/web/WebFrame.cpp
+++ b/third_party/WebKit/Source/web/WebFrame.cpp
@@ -4,8 +4,10 @@
 
 #include "public/web/WebFrame.h"
 
+#include <algorithm>
 #include "bindings/core/v8/WindowProxyManager.h"
 #include "core/HTMLNames.h"
+#include "core/dom/IncrementLoadEventDelayCount.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
@@ -22,7 +24,6 @@
 #include "web/RemoteFrameOwner.h"
 #include "web/WebLocalFrameImpl.h"
 #include "web/WebRemoteFrameImpl.h"
-#include <algorithm>
 
 namespace blink {
 
@@ -40,6 +41,16 @@ bool WebFrame::Swap(WebFrame* frame) {
   if (!old_frame->PrepareForCommit())
     return false;
 
+  // If there is a local parent, it might incorrectly declare itself complete
+  // during the detach phase of this swap. Suppress its completion until swap is
+  // over, at which point its completion will be correctly dependent on its
+  // newly swapped-in child.
+  std::unique_ptr<IncrementLoadEventDelayCount> delay_parent_load =

[lfg, 2017/04/27 17:08:25]

This looks good, but do you mind explaining why this wasn't needed before? It
seems that we are now calling CheckCompleted where we weren't before.

Also, by the time the detach happens, we already swapped the old frame from the
FrameTree, so why is the new frame allowed to declare itself complete?

+      parent_ && parent_->IsWebLocalFrame()
+          ? IncrementLoadEventDelayCount::Create(
+                *ToWebLocalFrameImpl(parent_)->GetFrame()->GetDocument())
+          : nullptr;
+
   if (parent_) {
     if (parent_->first_child_ == this)
       parent_->first_child_ = frame;