Set ComputedStyle on Node and use that in buildOwnLayout()

third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp

Index: third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp b/third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp
index b3aa972583655a4f649484ae413d06795c71b31f..343fdcf301ccfab366adcf8a953d7064888e088d 100644
--- a/third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/SliderThumbElement.cpp
@@ -74,7 +74,7 @@ void SliderThumbElement::setPositionFromValue()
     // Since the code to calculate position is in the LayoutSliderThumb layout
     // path, we don't actually update the value here. Instead, we poke at the
     // layoutObject directly to trigger layout.
-    if (layoutObject())
+    if (hasLayoutObject())
         layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
 }
 
@@ -163,7 +163,7 @@ void SliderThumbElement::setPositionFromPoint(const LayoutPoint& point)
 
     // FIXME: This is no longer being set from renderer. Consider updating the method name.
     input->setValueFromRenderer(valueString);
-    if (layoutObject())
+    if (hasLayoutObject())
         layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
 }
 
@@ -183,7 +183,7 @@ void SliderThumbElement::stopDragging()
     if (LocalFrame* frame = document().frame())
         frame->eventHandler().setCapturingMouseEventsNode(nullptr);
     m_inDragMode = false;
-    if (layoutObject())
+    if (hasLayoutObject())
         layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
     if (hostInput())
         hostInput()->dispatchFormControlChangeEvent();