Add UMA histogram Blink.PrePaint.UpdateTime

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index b9b322be5b1dbb6d6cfec3aee598b8d28b9381ab..441b325845338ba2ef7b137ee7fa1501073f65c2 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -2987,6 +2987,7 @@ void FrameView::performScrollAnchoringAdjustments() {
 
 void FrameView::updatePaintProperties() {
   TRACE_EVENT0("blink", "FrameView::updatePaintProperties");
+  SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.PrePaint.UpdateTime");
 
   if (!m_paintController)
     m_paintController = PaintController::create();