CSS Independent Transform Properties

Source/core/layout/compositing/CompositingReasonFinder.cpp

 // Copyright 2014 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 "config.h"
 #include "core/layout/compositing/CompositingReasonFinder.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/dom/Document.h"
 #include "core/frame/FrameView.h"
@@ skipping 125 matching lines @@
         reasons |= CompositingReasonReflectionWithCompositedDescendants;
 
     ASSERT(!(reasons & ~CompositingReasonComboAllStyleDeterminedReasons));
     return reasons;
 }
 
 bool CompositingReasonFinder::requiresCompositingForTransform(LayoutObject* layoutObject) const
 {
     // Note that we ask the layoutObject if it has a transform, because the style may have transforms,
     // but the layoutObject may be an inline that doesn't support them.
-    return layoutObject->hasTransformRelatedProperty() && layoutObject->style()->transform().has3DOperation();
+    return layoutObject->hasTransformRelatedProperty() && (layoutObject->style()->transform().has3DOperation() || layoutObject->style()->has3DTransformProperties());

[Eric Willigers, 2015/06/05 01:58:23]

Why not ensure hasTransformRelatedProperty returns true if
rotate/translate/scale are set?

Does hasTransformRelatedProperty already consider motion path?

[soonm, 2015/06/10 04:09:32]

hasTransformProperty will return True because I modified hasTransform but
has3DOperations also needs to be true here.

 }
 
 CompositingReasons CompositingReasonFinder::nonStyleDeterminedDirectReasons(const DeprecatedPaintLayer* layer) const
 {
     CompositingReasons directReasons = CompositingReasonNone;
     LayoutObject* layoutObject = layer->layoutObject();
 
     if (hasOverflowScrollTrigger()) {
         if (layer->clipParent())
             directReasons |= CompositingReasonOutOfFlowClipping;
@@ skipping 73 matching lines @@
             // Either way, we don't need to require compositing for scroll blocks on.  This avoids
             // enabling compositing by default, and avoids cluttering the root layers compositing reasons.
             return false;
         }
     }
 
     return true;
 }
 
 }