Remove minimumLayoutDelay() and associated machinery

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 8f69070bcd168e8d745d51fc690cd23f6f08c846..509682eb9af9c40cfca479ad942a8cea17b1535f 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -184,10 +184,6 @@ static const double cDefaultIncrementalRenderingSuppressionTimeoutInSeconds = 5;
 
 static const unsigned cMaxWriteRecursionDepth = 21;
 
-// This amount of time must have elapsed before we will even consider scheduling a layout without a delay.
-// FIXME: For faster machines this value can really be lowered to 200.  250 is adequate, but a little high
-// for dual G5s. :)
-static const int cLayoutScheduleThreshold = 250;
 
 // DOM Level 2 says (letters added):
 //
@@ -407,10 +403,8 @@ Document::Document(const DocumentInit& initializer, DocumentClassFlags documentC
     , m_cssTarget(0)
     , m_processingLoadEvent(false)
     , m_loadEventFinished(false)
-    , m_startTime(currentTime())
-    , m_overMinimumLayoutThreshold(false)
     , m_scriptRunner(ScriptRunner::create(this))
-    , m_xmlVersion("1.0")
+    , m_xmlVersion(ASCIILiteral("1.0"))
     , m_xmlStandalone(StandaloneUnspecified)
     , m_hasXMLDeclaration(0)
     , m_designMode(inherit)
@@ -1174,6 +1168,8 @@ void Document::setContent(const String& content)
     // pump the tokenizer syncrhonously and finish the parse.
     m_parser->pinToMainThread();
     m_parser->append(content.impl());
+    // FIXME: Append may yield for script execution.  Unclear if close()
+    // will wait for the parse to complete before returning or not.
     close();
 }
 
@@ -2242,25 +2238,12 @@ void Document::implicitClose()
         return;
     }
 
-    // Make sure both the initial layout and reflow happen after the onload
-    // fires. This will improve onload scores, and other browsers do it.
-    // If they wanna cheat, we can too. -dwh
-
-    if (frame()->navigationScheduler()->locationChangePending() && elapsedTime() < cLayoutScheduleThreshold) {
-        // Just bail out. Before or during the onload we were shifted to another page.
-        // The old i-Bench suite does this. When this happens don't bother painting or laying out.
-        m_processingLoadEvent = false;
-        view()->unscheduleRelayout();
-        return;
-    }
-
     frame()->loader()->checkCallImplicitClose();
     RenderObject* renderObject = renderer();
 
     // We used to force a synchronous display and flush here.  This really isn't
     // necessary and can in fact be actively harmful if pages are loading at a rate of > 60fps
     // (if your platform is syncing flushes and limiting them to 60fps).
-    m_overMinimumLayoutThreshold = true;
     if (!ownerElement() || (ownerElement()->renderer() && !ownerElement()->renderer()->needsLayout())) {
         updateStyleIfNeeded();
 
@@ -2315,26 +2298,9 @@ bool Document::shouldScheduleLayout()
         || (documentElement() && !isHTMLHtmlElement(documentElement()));
 }
 
-bool Document::isLayoutTimerActive()
-{
-    return view() && view()->layoutPending() && !minimumLayoutDelay();
-}
-
-int Document::minimumLayoutDelay()
-{
-    if (m_overMinimumLayoutThreshold)
-        return 0;
-
-    int elapsed = elapsedTime();
-    m_overMinimumLayoutThreshold = elapsed > cLayoutScheduleThreshold;
-
-    // We'll want to schedule the timer to fire at the minimum layout threshold.
-    return max(0, cLayoutScheduleThreshold - elapsed);
-}
-
-int Document::elapsedTime() const
+bool Document::parserShouldYieldAgressivelyBeforeFirstLayout()
 {
-    return static_cast<int>((currentTime() - m_startTime) * 1000);
+    return view() && view()->layoutPending();
 }
 
 void Document::write(const SegmentedString& text, Document* ownerDocument)