Throttle rendering pipeline for invisible iframes

Source/core/dom/DocumentLifecycle.cpp

Index: Source/core/dom/DocumentLifecycle.cpp
diff --git a/Source/core/dom/DocumentLifecycle.cpp b/Source/core/dom/DocumentLifecycle.cpp
index df8a50ab29080719d428eb1fcfcc92ca7be4119c..39c2a77edccbe6eba2e27118c9d17dc40d063224 100644
--- a/Source/core/dom/DocumentLifecycle.cpp
+++ b/Source/core/dom/DocumentLifecycle.cpp
@@ -65,6 +65,7 @@ DocumentLifecycle::DeprecatedTransition::~DeprecatedTransition()
 DocumentLifecycle::DocumentLifecycle()
     : m_state(Uninitialized)
     , m_detachCount(0)
+    , m_throttlingMode(ThrottlingMode::Disallow)
 {
 }
 
@@ -266,4 +267,14 @@ void DocumentLifecycle::ensureStateAtMost(State state)
     m_state = state;
 }
 
+void DocumentLifecycle::setThrottlingMode(ThrottlingMode throttlingMode)
+{
+    m_throttlingMode = throttlingMode;
+}
+
+DocumentLifecycle::ThrottlingMode DocumentLifecycle::throttlingMode() const
+{
+    return m_throttlingMode;
+}
+
 }