Paint invisible layer content in presence of composited animations.

third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PaintPropertyTreeBuilder.h"
 
 #include "core/dom/DOMNodeIds.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
@@ skipping 492 matching lines @@
     // clipped, so a blurred "B" may still be invisible.
     if (!filter.isEmpty()) {
       effectNodeNeeded = true;
       outputClip = context.current.clip;
 
       // TODO(trchen): A filter may contain spatial operations such that an
       // output pixel may depend on an input pixel outside of the output clip.
       // We should generate a special clip node to represent this expansion.
     }
 
-    CompositingReasons compositingReasons =
-        CompositingReasonFinder::requiresCompositingForEffectAnimation(style);

[wkorman, 2017/01/26 22:47:56]

This was a bug -- we were assigning the bool result to an int reason var. Now
fixed below.

[wkorman, 2017/01/27 03:53:12]

Added check for this to test case.

-    if (compositingReasons != CompositingReasonNone)
+    CompositingReasons compositingReasons = CompositingReasonNone;
+    if (CompositingReasonFinder::requiresCompositingForEffectAnimation(style)) {
+      compositingReasons = CompositingReasonActiveAnimation;
       effectNodeNeeded = true;
+    }
 
     CompositorElementId compositorElementId =
         (style.hasCurrentOpacityAnimation() ||
          style.hasCurrentFilterAnimation() ||
          style.hasCurrentBackdropFilterAnimation())
             ? createDomNodeBasedCompositorElementId(object)
             : CompositorElementId();
 
     if (effectNodeNeeded) {
       auto& properties = object.getMutableForPainting().ensurePaintProperties();
@@ skipping 469 matching lines @@
   updateOverflowClip(object, context);
   updatePerspective(object, context);
   updateSvgLocalToBorderBoxTransform(object, context);
   updateScrollAndScrollTranslation(object, context);
   updateOutOfFlowContext(object, context);
 
   context.forceSubtreeUpdate |= object.subtreeNeedsPaintPropertyUpdate();
 }
 
 }  // namespace blink