Fix geometry mapping issues for float under inline

third_party/WebKit/Source/core/layout/LayoutGeometryMap.cpp

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 186 matching lines @@
     const ComputedStyle& style = current->styleRef();
     if (style.position() == FixedPosition || style.isFlippedBlocksWritingMode())
       return false;
 
     if (current->style()->canContainFixedPositionObjects() ||
         current->isLayoutFlowThread() || current->isSVGRoot())
       return false;
 
     if (current == ancestor)
       break;
+
+    if (current->isFloating() && current->parent() &&

[wkorman, 2017/01/04 22:27:08]

Some concern re: unexpected ramifications of this, but indirect callsites look
limited to CompositingInputsUpdater and ScrollingCoordinator. It doesn't look
like there are any existing unit tests for this class. It seems worth adding
some if this is expected to be long-lived code, at least to cover this newly
added logic initially.

Perhaps add eae@ or szager@ to get layout team input.

[Xianzhu, 2017/01/04 22:49:59]

The unit test is here:
https://codereview.chromium.org/2575423003/diff2/100001:160001/third_party/We....

This function should return false if the parent-child relationship of
PaintLayers is different from the container-containee relationship of the
layers' objects.

+        !current->parent()->isLayoutBlock())
+      return false;
   }
 
   return true;
 }
 
 void LayoutGeometryMap::pushMappingsToAncestor(
     const PaintLayer* layer,
     const PaintLayer* ancestorLayer) {
   const LayoutObject* layoutObject = layer->layoutObject();
 
@@ skipping 152 matching lines @@
   // If we're not working with multiple LayoutViews, then any view is considered
   // "topmost" (to preserve original behavior).
   if (!(m_mapCoordinatesFlags & TraverseDocumentBoundaries))
     return true;
 
   return layoutObject->frame()->isMainFrame();
 }
 #endif
 
 }  // namespace blink