Replace RenderArena with PartitionAlloc.

Source/core/page/Page.cpp

Index: Source/core/page/Page.cpp
diff --git a/Source/core/page/Page.cpp b/Source/core/page/Page.cpp
index 06702aecd8b41dd13872923cb95c3f5ccd7f1426..9465079f925f24c0670efe494c4adb7f8bc7c9ba 100644
--- a/Source/core/page/Page.cpp
+++ b/Source/core/page/Page.cpp
@@ -68,7 +68,6 @@
 #include "core/platform/Widget.h"
 #include "core/platform/network/NetworkStateNotifier.h"
 #include "core/plugins/PluginData.h"
-#include "core/rendering/RenderArena.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/RenderWidget.h"
@@ -189,20 +188,6 @@ Page::~Page()
 #endif
 }
 
-ArenaSize Page::renderTreeSize() const
-{
-    ArenaSize total(0, 0);
-    for (Frame* frame = mainFrame(); frame; frame = frame->tree()->traverseNext()) {
-        if (!frame->document())
-            continue;
-        if (RenderArena* arena = frame->document()->renderArena()) {
-            total.treeSize += arena->totalRenderArenaSize();
-            total.allocated += arena->totalRenderArenaAllocatedBytes();
-        }
-    }
-    return total;
-}
-
 ViewportArguments Page::viewportArguments() const
 {
     return mainFrame() && mainFrame()->document() ? mainFrame()->document()->viewportArguments() : ViewportArguments();