Oilpan: Move ChromeClient classes into Oilpan heap.

Source/core/page/Page.h

Index: Source/core/page/Page.h
diff --git a/Source/core/page/Page.h b/Source/core/page/Page.h
index 783f306e6c1a6852dbc936d5fd93b5774afe8384..bfce8a7a1d2515d9af1994096f9bcc9ac3c65061 100644
--- a/Source/core/page/Page.h
+++ b/Source/core/page/Page.h
@@ -76,13 +76,14 @@ public:
     static void platformColorsChanged();
 
     // It is up to the platform to ensure that non-null clients are provided where required.
-    struct CORE_EXPORT PageClients {
-        WTF_MAKE_NONCOPYABLE(PageClients); WTF_MAKE_FAST_ALLOCATED(PageClients);
+    struct CORE_EXPORT PageClients final {
+        STACK_ALLOCATED();
+        WTF_MAKE_NONCOPYABLE(PageClients);
     public:
         PageClients();
         ~PageClients();
 
-        ChromeClient* chromeClient;
+        RawPtrWillBeMember<ChromeClient> chromeClient;
         ContextMenuClient* contextMenuClient;
         EditorClient* editorClient;
         DragClient* dragClient;