Separate forced subtree invalidation reasons for location change and SVG resource change

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

 // Copyright 2016 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/ObjectPaintInvalidator.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LayoutPartItem.h"
@@ skipping 516 matching lines @@
   // selection rect regardless.
   invalidateSelectionIfNeeded(reason);
 
   switch (reason) {
     case PaintInvalidationNone:
       // TODO(trchen): Currently we don't keep track of paint offset of layout
       // objects.  There are corner cases that the display items need to be
       // invalidated for paint offset mutation, but incurs no pixel difference
       // (i.e. bounds stay the same) so no rect-based invalidation is issued.
       // See crbug.com/508383 and crbug.com/515977.  This is a workaround to
-      // force display items to update paint offset.
-      if (m_context.forcedSubtreeInvalidationFlags &
-          PaintInvalidatorContext::ForcedSubtreeInvalidationChecking) {
+      // force display items to update paint offset. Exclude non-root SVG whose
+      // paint offset is always zero.
+      if ((!m_object.isSVG() || m_object.isSVGRoot()) &&
+          (m_context.forcedSubtreeInvalidationFlags &
+           PaintInvalidatorContext::ForcedSubtreeInvalidationChecking)) {
         reason = PaintInvalidationLocationChange;
         break;
       }
+      if (m_object.isSVG() &&
+          (m_context.forcedSubtreeInvalidationFlags &
+           PaintInvalidatorContext::ForcedSubtreeSVGResourceChange)) {
+        reason = PaintInvalidationSVGResourceChange;
+        break;
+      }
       return PaintInvalidationNone;
     case PaintInvalidationDelayedFull:
       return PaintInvalidationDelayedFull;
     default:
       DCHECK(isImmediateFullPaintInvalidationReason(reason));
       fullyInvalidatePaint(reason, m_context.oldVisualRect,
                            m_context.newVisualRect);
   }
 
   m_context.paintingLayer->setNeedsRepaint();
   m_object.invalidateDisplayItemClients(reason);
   return reason;
 }
 
 DisablePaintInvalidationStateAsserts::DisablePaintInvalidationStateAsserts()
     : m_disabler(&gDisablePaintInvalidationStateAsserts, true) {}
 
 }  // namespace blink