Advance document lifecycle to CompositingClean prior to hit testing

Source/core/dom/DocumentLifecycle.cpp

 /*
  * Copyright (C) 2013 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 112 matching lines @@
         // can happen when we call layout recursively and we unwind the stack.
         if (state == LayoutClean)
             return true;
         if (state == StyleClean)
             return true;
         return false;
     }
     if (m_state == CompositingClean) {
         if (state == InStyleRecalc)
             return true;
+        if (state == InPreLayout)

[leviw_travelin_and_unemployed, 2015/03/12 20:09:32]

Why this change?

[qiankun, 2015/03/13 03:23:10]

When running layout test, LayoutTreeAsText::writeLayers() will call layout()
again after hit testing. If we don't allow changing state from CompositingClean
to InPreLayout, layout test will crash. Attached crash stack for running
fast/css/resize-corner-tracking.html:
#0 0x0000008bd59e base::debug::StackTrace::StackTrace()
#1 0x0000008bd0d3 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7ffbe87e4210 <unknown>
#3 0x00000283e7d4 blink::DocumentLifecycle::advanceTo()
#4 0x000002ee3b4f blink::FrameView::performPreLayoutTasks()
#5 0x000002ee4b39 blink::FrameView::layout()
#6 0x0000033d9b89 blink::write()
#7 0x0000033daf31 blink::write()
#8 0x0000033da3f0 blink::LayoutTreeAsText::writeLayers()
#9 0x0000033da52d blink::LayoutTreeAsText::writeLayers()
#10 0x0000033da685 blink::LayoutTreeAsText::writeLayers()
#11 0x0000033db300 blink::externalRepresentation()
#12 0x0000033db220 blink::externalRepresentation()
#13 0x000002212cff blink::WebLocalFrameImpl::layoutTreeAsText()
#14 0x000000527d7c content::WebTestProxyBase::CaptureTree()
#15 0x00000051be34 content::WebKitTestRunner::CaptureDump()
#16 0x00000051bb1c content::WebKitTestRunner::TestFinished()
#17 0x00000051c0ac content::WebKitTestRunner::TestFinished()
#18 0x00000058fab4 content::TestRunner::WorkQueue::ProcessWorkSoon()
#19 0x000000590e65 content::TestRunner::LocationChangeDone()
#20 0x000000590dbe content::TestRunner::setTopLoadingFrame()

[esprehn, 2015/03/24 23:06:05]

I think this is a bug in LayoutTreeAsText::writeLayers, it wants to do
view->document()->updateLayout() instead.

+            return true;
         if (state == InCompositingUpdate)
             return true;
         if (state == InPaintInvalidation)
             return true;
         return false;
     }
     if (m_state == InPaintInvalidation) {
         if (state == PaintInvalidationClean)
             return true;
         return false;
@@ skipping 29 matching lines @@
 void DocumentLifecycle::ensureStateAtMost(State state)
 {
     ASSERT(state == VisualUpdatePending || state == StyleClean || state == LayoutClean);
     if (m_state <= state)
         return;
     ASSERT(canRewindTo(state));
     m_state = state;
 }
 
 }