For SPv2, move updateAnimations() to follow scrolling and paint invalidation.

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 e1b62509b08c745affd26a7a3a85dcc10a194dd6..84f4946dba1d674fa331ca3a2a0ec308034fe441 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -2873,8 +2873,6 @@ void FrameView::updateLifecyclePhasesInternal(
       if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
         view.compositor()->updateIfNeededRecursive();
       } else {
-        DocumentAnimations::updateAnimations(layoutView()->document());
-
         forAllNonThrottledFrameViews([](FrameView& frameView) {
           frameView.layoutView()->layer()->updateDescendantDependentFlags();
           frameView.layoutView()->commitPendingSelection();
@@ -2904,6 +2902,9 @@ void FrameView::updateLifecyclePhasesInternal(
       updatePaintProperties();
     }
 
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+      DocumentAnimations::updateAnimations(layoutView()->document());

[wkorman, 2016/12/15 20:14:04]

Two notes:

1. This moves some work that used to be captured within tracing for
("devtools.timeline", "UpdateLayerTree") out of that tracing block for SPv2. I
think that's fine given overarching SPv2 compositing architecture change but
wanted to note before we potentially land this.

2. I am not sure whether it is safe to move updateAnimations() to follow
scrollContentsIfNeededRecursive(). We can try it and see unless you've existing
insight. It looks like it may be ok since FrameView::scrollContentsSlowPath()
looks mostly legacy as all of the is-composited checks there will be skipped in
SPv2, leaving only some paint invalidation, which shouldn't affect animations;
and, FrameView::frameRectsChanged() which is also therein also looks
animation-safe.

+
     if (targetState == DocumentLifecycle::PaintClean) {
       if (!m_frame->document()->printing())
         synchronizedPaint();