Remove anonymous block wrapper when all children become inline

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

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 75fabaddfae7c3372eb547349e52000fce1ab42a..24a4a0f90a651229ac588dd53af26fafad1afc94 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -607,7 +607,7 @@ static bool canMergeContiguousAnonymousBlocks(LayoutObject* oldChild, LayoutObje
 void LayoutBlock::removeAnonymousWrappersIfRequired()
 {
     ASSERT(isLayoutBlockFlow());
-    Vector<LayoutBox*, 16> blocksToRemove;
+    Vector<LayoutBox*, 3> blocksToRemove;
     for (LayoutBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
         if (child->isFloatingOrOutOfFlowPositioned())
             continue;
@@ -646,18 +646,22 @@ void LayoutBlock::collapseAnonymousBlockChild(LayoutBlock* parent, LayoutBlock*
     child->destroy();
 }
 
-static inline bool shouldMakeChildrenInline(const LayoutBlock* block)
+void LayoutBlock::makeChildrenInlineIfPossible()

[mstensho (USE GERRIT), 2015/10/26 13:42:46]

Before doing anything (object type checks and establishing the Vector), how
about first checking if we have children at all? I.e. move the |child|
definition a few lines up and bail early if it's nullptr.

 {
-    if (!block->isLayoutBlockFlow())
-        return false;
-    LayoutObject* child = block->firstChild();
+    if (!isLayoutBlockFlow() || isRubyRun())

[mstensho (USE GERRIT), 2015/10/26 13:42:46]

I'm wondering if we need more checks here. What about continuations and
LayoutRubyBase? I'm looking at canMergeContiguousAnonymousBlocks()... Not sure
if it's possible to end up with anonymous ruby base siblings or anything, but...

+        return;
+    Vector<LayoutBlock*, 3> blocksToRemove;
+    LayoutObject* child = firstChild();
     while (child) {
-        // TODO(rhogan): If we encounter anonymous blocks with inline children we should fold them in here.
-        if (!child->isFloatingOrOutOfFlowPositioned())
-            return false;
+        if (child->isAnonymousBlock() && child->childrenInline())
+            blocksToRemove.append(toLayoutBlock(child));
+        else if (!child->isFloatingOrOutOfFlowPositioned())
+            return;
         child = child->nextSibling();
     }
-    return true;
+    for (size_t i = 0; i < blocksToRemove.size(); i++)
+        collapseAnonymousBlockChild(this, blocksToRemove[i]);
+    setChildrenInline(true);
 }
 
 void LayoutBlock::removeChild(LayoutObject* oldChild)
@@ -762,9 +766,9 @@ void LayoutBlock::removeChild(LayoutObject* oldChild)
             setContinuation(nullptr);
             destroy();
         }
-    } else if (!beingDestroyed() && !oldChild->isFloatingOrOutOfFlowPositioned() && shouldMakeChildrenInline(this)) {
+    } else if (!beingDestroyed() && !oldChild->isFloatingOrOutOfFlowPositioned()) {
         // If the child we're removing means that we can now treat all children as inline without the need for anonymous blocks, then do that.
-        setChildrenInline(true);
+        makeChildrenInlineIfPossible();
     }
 }