Avoid mutating frame owner when detaching a provisional frame.

third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 271 matching lines @@
 
 void WebViewHelper::resize(WebSize size) {
   m_testWebViewClient->clearAnimationScheduled();
   webView()->resize(size);
   EXPECT_FALSE(m_testWebViewClient->animationScheduled());
   m_testWebViewClient->clearAnimationScheduled();
 }
 
 TestWebFrameClient::TestWebFrameClient() {}
 
+// TODO(dcheng): https://crbug.com/578349 tracks the removal of this code. This
+// override exists only to handle the confusing provisional frame case.
+void TestWebFrameClient::frameDetached(WebLocalFrame* frame, DetachType type) {
+  if (type == DetachType::Remove && frame->parent()) {
+    // Since this may be detaching a provisional frame, make sure |child| is
+    // actually linked into the frame tree (i.e. it is present in its parent
+    // node's children list) before trying to remove it as a child.
+    for (WebFrame* child = frame->parent()->firstChild(); child;
+         child = child->nextSibling()) {
+      if (child == frame)
+        frame->parent()->removeChild(frame);
+    }
+  }
+
+  if (frame->frameWidget())
+    frame->frameWidget()->close();
+
+  frame->close();
+}
+
 WebLocalFrame* TestWebFrameClient::createChildFrame(
     WebLocalFrame* parent,
     WebTreeScopeType scope,
     const WebString& name,
     const WebString& uniqueName,
     WebSandboxFlags sandboxFlags,
     const WebFrameOwnerProperties& frameOwnerProperties) {
   WebLocalFrame* frame = WebLocalFrame::create(scope, this);
   parent->appendChild(frame);
   return frame;
@@ skipping 32 matching lines @@
   m_testWebViewClient->scheduleAnimation();
 }
 
 void TestWebViewWidgetClient::didMeaningfulLayout(
     WebMeaningfulLayout layoutType) {
   m_testWebViewClient->didMeaningfulLayout(layoutType);
 }
 
 }  // namespace FrameTestHelpers
 }  // namespace blink