Replace RenderArena with PartitionAlloc

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index 376a739140520cab245ee520d644e3c46b0efdc8..c60e8fba8c2910031fffbd970a1f440680f253a3 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -44,12 +44,12 @@
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/page/animation/AnimationController.h"
+#include "core/platform/Partitions.h"
 #include "core/platform/graphics/FloatQuad.h"
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/transforms/TransformState.h"
 #include "core/rendering/FlowThreadController.h"
 #include "core/rendering/HitTestResult.h"
-#include "core/rendering/RenderArena.h"
 #include "core/rendering/RenderCounter.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
@@ -91,7 +91,6 @@ namespace WebCore {
 using namespace HTMLNames;
 
 #ifndef NDEBUG
-static void* baseOfRenderObjectBeingDeleted;
 
 RenderObject::SetLayoutNeededForbiddenScope::SetLayoutNeededForbiddenScope(RenderObject* renderObject, bool isForbidden)
     : m_renderObject(renderObject)
@@ -121,30 +120,26 @@ bool RenderObject::s_affectsParentBlock = false;
 
 RenderObjectAncestorLineboxDirtySet* RenderObject::s_ancestorLineboxDirtySet = 0;
 
-void* RenderObject::operator new(size_t sz, RenderArena* renderArena)
+void* RenderObject::operator new(size_t sz)
 {
-    return renderArena->allocate(sz);
+    return partitionAlloc(Partitions::getRenderingPartition(), sz);
 }
 
-void RenderObject::operator delete(void* ptr, size_t sz)
+void RenderObject::operator delete(void* ptr)
 {
-    ASSERT(baseOfRenderObjectBeingDeleted == ptr);
-
-    // Stash size where destroy can find it.
-    *(size_t *)ptr = sz;
+    partitionFree(ptr);
 }
 
 RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
 {
     Document* doc = element->document();
-    RenderArena* arena = doc->renderArena();
 
     // Minimal support for content properties replacing an entire element.
     // Works only if we have exactly one piece of content and it's a URL.
     // Otherwise acts as if we didn't support this feature.
     const ContentData* contentData = style->contentData();
     if (contentData && !contentData->next() && contentData->isImage() && !element->isPseudoElement()) {
-        RenderImage* image = new (arena) RenderImage(element);
+        RenderImage* image = new RenderImage(element);
         // RenderImageResourceStyleImage requires a style being present on the image but we don't want to
         // trigger a style change now as the node is not fully attached. Moving this code to style change
         // doesn't make sense as it should be run once at renderer creation.
@@ -160,56 +155,56 @@ RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
 
     if (element->hasTagName(rubyTag)) {
         if (style->display() == INLINE)
-            return new (arena) RenderRubyAsInline(element);
+            return new RenderRubyAsInline(element);
         else if (style->display() == BLOCK)
-            return new (arena) RenderRubyAsBlock(element);
+            return new RenderRubyAsBlock(element);
     }
     // treat <rt> as ruby text ONLY if it still has its default treatment of block
     if (element->hasTagName(rtTag) && style->display() == BLOCK)
-        return new (arena) RenderRubyText(element);
+        return new RenderRubyText(element);
     if (RuntimeEnabledFeatures::cssRegionsEnabled() && style->isDisplayRegionType() && !style->regionThread().isEmpty() && doc->renderView())
-        return new (arena) RenderRegion(element, 0);
+        return new RenderRegion(element, 0);
     switch (style->display()) {
     case NONE:
         return 0;
     case INLINE:
-        return new (arena) RenderInline(element);
+        return new RenderInline(element);
     case BLOCK:
     case INLINE_BLOCK:
     case RUN_IN:
     case COMPACT:
         if ((!style->hasAutoColumnCount() || !style->hasAutoColumnWidth()) && doc->regionBasedColumnsEnabled())
-            return new (arena) RenderMultiColumnBlock(element);
-        return new (arena) RenderBlock(element);
+            return new RenderMultiColumnBlock(element);
+        return new RenderBlock(element);
     case LIST_ITEM:
-        return new (arena) RenderListItem(element);
+        return new RenderListItem(element);
     case TABLE:
     case INLINE_TABLE:
-        return new (arena) RenderTable(element);
+        return new RenderTable(element);
     case TABLE_ROW_GROUP:
     case TABLE_HEADER_GROUP:
     case TABLE_FOOTER_GROUP:
-        return new (arena) RenderTableSection(element);
+        return new RenderTableSection(element);
     case TABLE_ROW:
-        return new (arena) RenderTableRow(element);
+        return new RenderTableRow(element);
     case TABLE_COLUMN_GROUP:
     case TABLE_COLUMN:
-        return new (arena) RenderTableCol(element);
+        return new RenderTableCol(element);
     case TABLE_CELL:
-        return new (arena) RenderTableCell(element);
+        return new RenderTableCell(element);
     case TABLE_CAPTION:
-        return new (arena) RenderTableCaption(element);
+        return new RenderTableCaption(element);
     case BOX:
     case INLINE_BOX:
-        return new (arena) RenderDeprecatedFlexibleBox(element);
+        return new RenderDeprecatedFlexibleBox(element);
     case FLEX:
     case INLINE_FLEX:
-        return new (arena) RenderFlexibleBox(element);
+        return new RenderFlexibleBox(element);
     case GRID:
     case INLINE_GRID:
-        return new (arena) RenderGrid(element);
+        return new RenderGrid(element);
     case LAZY_BLOCK:
-        return new (arena) RenderLazyBlock(element);
+        return new RenderLazyBlock(element);
     }
 
     return 0;
@@ -2634,11 +2629,12 @@ void RenderObject::destroyAndCleanupAnonymousWrappers()
 void RenderObject::destroy()
 {
     willBeDestroyed();
-    arenaDelete(renderArena(), this);
+    postDestroy();
 }
 
-void RenderObject::arenaDelete(RenderArena* arena, void* base)
+void RenderObject::postDestroy()
 {
+    // It seems ugly that this is not in willBeDestroyed().
     if (m_style) {
         for (const FillLayer* bgLayer = m_style->backgroundLayers(); bgLayer; bgLayer = bgLayer->next()) {
             if (StyleImage* backgroundImage = bgLayer->image())
@@ -2657,17 +2653,7 @@ void RenderObject::arenaDelete(RenderArena* arena, void* base)
             maskBoxImage->removeClient(this);
     }
 
-#ifndef NDEBUG
-    void* savedBase = baseOfRenderObjectBeingDeleted;
-    baseOfRenderObjectBeingDeleted = base;
-#endif
     delete this;
-#ifndef NDEBUG
-    baseOfRenderObjectBeingDeleted = savedBase;
-#endif
-
-    // Recover the size left there for us by operator delete and free the memory.
-    arena->free(*(size_t*)base, base);
 }
 
 VisiblePosition RenderObject::positionForPoint(const LayoutPoint&)