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 dfe3167499f4eb0c9bd22e9339cc9621921d009b..d5e4cd2e06e124d95f95c26a66a27093e202f022 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -642,18 +642,22 @@ void LayoutBlock::collapseAnonymousBlockChild(LayoutBlock* parent, LayoutBlock*
     child->destroy();
 }
 
-static inline bool shouldMakeChildrenInline(const LayoutBlock* block)
+void LayoutBlock::makeChildrenInlineIfPossible()
 {
-    if (!block->isLayoutBlockFlow())
-        return false;
-    LayoutObject* child = block->firstChild();
+    if (!isLayoutBlockFlow() || isRubyRun())

[mstensho (USE GERRIT), 2015/10/22 19:19:57]

Where does the ruby check come from? Do we have a test that would fail without
it?

+        return;
+    Vector<LayoutBox*, 16> blocksToRemove;

[mstensho (USE GERRIT), 2015/10/22 19:19:58]

How many anonymous blocks can we possibly find here? Two at most, right?

+    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(toLayoutBox(child));
+        else if (!child->isFloatingOrOutOfFlowPositioned())
+            return;
         child = child->nextSibling();
     }
-    return true;
+    for (size_t i = 0; i < blocksToRemove.size(); i++)
+        collapseAnonymousBlockChild(this, toLayoutBlock(blocksToRemove[i]));

[mstensho (USE GERRIT), 2015/10/22 19:19:58]

Looks like blocksToRemove should hold LayoutBlock pointers, so you don't need to
cast it here.

+    setChildrenInline(true);
 }
 
 void LayoutBlock::removeChild(LayoutObject* oldChild)
@@ -758,9 +762,9 @@ 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();
     }
 }