Begin tracking why layout is invalidated

Source/core/html/shadow/SliderThumbElement.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 60 matching lines @@
     element->setAttribute(idAttr, ShadowElementNames::sliderThumb());
     return element.release();
 }
 
 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
     // renderer directly to trigger layout.
     if (layoutObject())
-        layoutObject()->setNeedsLayoutAndFullPaintInvalidation();
+        layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
 }
 
 LayoutObject* SliderThumbElement::createLayoutObject(const ComputedStyle&)
 {
     return new LayoutSliderThumb(this);
 }
 
 bool SliderThumbElement::isDisabledFormControl() const
 {
     return hostInput() && hostInput()->isDisabledFormControl();
@@ skipping 69 matching lines @@
             value = closest;
     }
 
     String valueString = serializeForNumberType(value);
     if (valueString == input->value())
         return;
 
     // FIXME: This is no longer being set from renderer. Consider updating the method name.
     input->setValueFromRenderer(valueString);
     if (layoutObject())
-        layoutObject()->setNeedsLayoutAndFullPaintInvalidation();
+        layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
 }
 
 void SliderThumbElement::startDragging()
 {
     if (LocalFrame* frame = document().frame()) {
         frame->eventHandler().setCapturingMouseEventsNode(this);
         m_inDragMode = true;
     }
 }
 
 void SliderThumbElement::stopDragging()
 {
     if (!m_inDragMode)
         return;
 
     if (LocalFrame* frame = document().frame())
         frame->eventHandler().setCapturingMouseEventsNode(nullptr);
     m_inDragMode = false;
     if (layoutObject())
-        layoutObject()->setNeedsLayoutAndFullPaintInvalidation();
+        layoutObject()->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SliderValueChanged);
     if (hostInput())
         hostInput()->dispatchFormControlChangeEvent();
 }
 
 void SliderThumbElement::defaultEventHandler(Event* event)
 {
     if (!event->isMouseEvent()) {
         HTMLDivElement::defaultEventHandler(event);
         return;
     }
@@ skipping 125 matching lines @@
     case MediaVolumeSliderThumbPart:
     case MediaFullScreenVolumeSliderPart:
     case MediaFullScreenVolumeSliderThumbPart:
         return mediaSliderContainer;
     default:
         return sliderContainer;
     }
 }
 
 }