Add Blink.PrePaint.UpdateTime as an alias of Blink.PaintInvalidation.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 e9af56f59fac9f39a92d03b2917a03a4708c5416..d76f103605d5c5d3c618d1595e0a3e9882ae59ba 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -3190,7 +3190,11 @@ void FrameView::updateStyleAndLayoutIfNeededRecursiveInternal() {
 
 void FrameView::invalidateTreeIfNeededRecursive() {
   SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.PaintInvalidation.UpdateTime");
-  invalidateTreeIfNeededRecursiveInternal();
+  {
+    // For comparison to SlimmingPaintInvalidation.
+    SCOPED_BLINK_UMA_HISTOGRAM_TIMER("Blink.PrePaint.UpdateTime");
+    invalidateTreeIfNeededRecursiveInternal();
+  }
 }
 
 void FrameView::invalidateTreeIfNeededRecursiveInternal() {