Call LocalDOMWindow::clearDocument when a frame gets detached

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 0fdb26ccb0f139a5f54035d955b156ae921ace7a..d6a2a7af6c450fce05ae93c35089200e64111a0c 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -4508,9 +4508,12 @@ void FrameView::updateRenderThrottlingStatusForTesting() {
 
 void FrameView::updateRenderThrottlingStatus(bool hidden,
                                              bool subtreeThrottled) {
+  if (!m_frame->document())
+    return;
+
   TRACE_EVENT0("blink", "FrameView::updateRenderThrottlingStatus");
   DCHECK(!isInPerformLayout());
-  DCHECK(!m_frame->document() || !m_frame->document()->inStyleRecalc());
+  DCHECK(!m_frame->document()->inStyleRecalc());
   bool wasThrottled = canThrottleRendering();
 
   // Note that we disallow throttling of 0x0 frames because some sites use
@@ -4574,7 +4577,7 @@ void FrameView::updateRenderThrottlingStatus(bool hidden,
 // recordDeferredLoadReason().
 void FrameView::maybeRecordLoadReason() {
   FrameView* parent = parentFrameView();
-  if (frame().document()->frame()) {
+  if (frame().document() && frame().document()->frame()) {
     if (!parent) {
       HTMLFrameOwnerElement* element = frame().deprecatedLocalOwner();
       if (!element)