Centralize deferred commit conditions.

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 26b33075eb8218667929384816530a6a3338dc64..fc70d14a59351ddd55664b363a1ab122e26b7481 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -367,6 +367,7 @@ Document::Document(const DocumentInit& initializer, DocumentClassFlags documentC
     , TreeScope(*this)
     , m_hasNodesWithPlaceholderStyle(false)
     , m_evaluateMediaQueriesOnStyleRecalc(false)
+    , m_shouldProcessFrameLifecycle(false)
     , m_pendingSheetLayout(NoLayoutWithPendingSheets)
     , m_frame(initializer.frame())
     , m_domWindow(m_frame ? m_frame->localDOMWindow() : 0)
@@ -5086,6 +5087,19 @@ void Document::pluginLoadingTimerFired(Timer<Document>*)
     updateLayout();
 }
 
+bool Document::shouldProcessFrameLifecycle()
+{
+    if (m_shouldProcessFrameLifecycle)
+        return true;
+    if (!isRenderingReady())
+        return false;
+    if ((isHTMLDocument() || isXHTMLDocument()) && !body() && parsing())
+        return false;
+    // Once the page starts processing the pipeline we should never stop.
+    m_shouldProcessFrameLifecycle = true;
+    return true;
+}
+
 ScriptedAnimationController& Document::ensureScriptedAnimationController()
 {
     if (!m_scriptedAnimationController) {