[Reland] Remove style spans to follow the styles of the block element

third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp

Index: third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp b/third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp
index cfbeebd84a333bfa091068ee7b29239729958a04..47ff6f38c8a31c597bc1634013a79dec4639d813 100644
--- a/third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/ReplaceSelectionCommand.cpp
@@ -35,6 +35,7 @@
 #include "core/dom/Document.h"
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/Element.h"
+#include "core/dom/NodeComputedStyle.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/FrameSelection.h"
@@ -794,6 +795,23 @@ static void removeHeadContents(ReplacementFragment& fragment)
     }
 }
 
+static bool followBlockElementStyle(const Node* node)
+{
+    if (!node->isHTMLElement())
+        return false;
+
+    const HTMLElement& element = toHTMLElement(*node);
+    return element.computedStyle()->display() == LIST_ITEM
+        || element.computedStyle()->display() == TABLE_CELL
+        || element.hasTagName(preTag)
+        || element.hasTagName(h1Tag)
+        || element.hasTagName(h2Tag)
+        || element.hasTagName(h3Tag)
+        || element.hasTagName(h4Tag)
+        || element.hasTagName(h5Tag)
+        || element.hasTagName(h6Tag);
+}
+
 // Remove style spans before insertion if they are unnecessary.  It's faster because we'll
 // avoid doing a layout.
 static bool handleStyleSpansBeforeInsertion(ReplacementFragment& fragment, const Position& insertionPos)
@@ -807,10 +825,20 @@ static bool handleStyleSpansBeforeInsertion(ReplacementFragment& fragment, const
     if (isMailPasteAsQuotationHTMLBlockQuoteElement(topNode) || enclosingNodeOfType(firstPositionInOrBeforeNode(topNode), isMailHTMLBlockquoteElement, CanCrossEditingBoundary))
         return false;
 
-    // Remove style spans to follow the styles of list item when |fragment| becomes a list item.
-    // See bug http://crbug.com/335955.
+    // Remove style spans to follow the styles of parent block element when |fragment| becomes a part of it.
+    // See bugs http://crbug.com/226941 and http://crbug.com/335955.
     HTMLSpanElement* wrappingStyleSpan = toHTMLSpanElement(topNode);
-    if (isListItem(enclosingBlock(insertionPos.anchorNode()))) {
+    const Node* node = insertionPos.anchorNode();
+    // |node| can be an inline element like <br> under <li>
+    // e.g.) editing/execCommand/switch-list-type.html
+    //       editing/deleting/backspace-merge-into-block.html
+    if (node->computedStyle()->display() == INLINE) {
+        node = enclosingBlock(insertionPos.anchorNode());
+        if (!node)
+            return false;
+    }
+
+    if (followBlockElementStyle(node)) {
         fragment.removeNodePreservingChildren(wrappingStyleSpan);
         return true;
     }