Calling container() on floats should only skip LayoutInline ancestors.

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index e913d31e1340f849c08cc1f8b86a41dd5aee504c..1e2b3b75c8fca137cdf97d7d31b046c71c391b01 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -2504,8 +2504,17 @@ LayoutObject* LayoutObject::container(AncestorSkipInfo* skipInfo) const {
     return multicolContainer;
   }
 
-  if (isFloating())
-    return containingBlock(skipInfo);
+  if (isFloating()) {
+    // Skip non-atomic inline ancestors, but nothing else. We want to stop at
+    // e.g. LayoutMedia objects, since they act as containing blocks but do not
+    // inherit from LayoutBlock (so we cannot just use containingBlock() here).
+    for (LayoutObject* walker = parent(); walker; walker = walker->parent()) {
+      if (!walker->isLayoutInline())
+        return walker;
+      if (skipInfo)
+        skipInfo->update(*walker);
+    }
+  }
 
   return parent();
 }