Reset m_didTransformToRootUpdate flag during invalidationTreeIfNeeded

Source/core/rendering/svg/RenderSVGViewportContainer.cpp

Index: Source/core/rendering/svg/RenderSVGViewportContainer.cpp
diff --git a/Source/core/rendering/svg/RenderSVGViewportContainer.cpp b/Source/core/rendering/svg/RenderSVGViewportContainer.cpp
index 5481703192074555ea9aac55a3cc5e9219431373..d12790d1d1a9bc202e938d99682d39a5be21381d 100644
--- a/Source/core/rendering/svg/RenderSVGViewportContainer.cpp
+++ b/Source/core/rendering/svg/RenderSVGViewportContainer.cpp
@@ -74,7 +74,9 @@ void RenderSVGViewportContainer::calcViewport()
 
 bool RenderSVGViewportContainer::calculateLocalTransform()
 {
-    m_didTransformToRootUpdate = m_needsTransformUpdate || SVGRenderSupport::transformToRootChanged(parent());
+    if (m_needsTransformUpdate || SVGRenderSupport::transformToRootChanged(parent()))
+        m_didTransformToRootUpdate = true;
+
     if (!m_needsTransformUpdate)
         return false;
 
@@ -113,4 +115,12 @@ void RenderSVGViewportContainer::paint(PaintInfo& paintInfo, const LayoutPoint&
     RenderSVGContainer::paint(paintInfo, paintOffset);
 }
 
+void RenderSVGViewportContainer::clearPaintInvalidationState()
+{
+    RenderSVGContainer::clearPaintInvalidationState();
+
+    ASSERT(!m_needsTransformUpdate);
+    m_didTransformToRootUpdate = false;
+}
+
 }