Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXARIAGridRow.cpp

Index: Source/modules/accessibility/AXARIAGridRow.cpp
diff --git a/Source/modules/accessibility/AXARIAGridRow.cpp b/Source/modules/accessibility/AXARIAGridRow.cpp
index e27e0bcd88ce59add20a231873ee0b5076650f27..82df84dc7ba5176ae0c5a59078b2d43e00350d6e 100644
--- a/Source/modules/accessibility/AXARIAGridRow.cpp
+++ b/Source/modules/accessibility/AXARIAGridRow.cpp
@@ -35,7 +35,7 @@
 
 namespace blink {
 
-AXARIAGridRow::AXARIAGridRow(LayoutObject* layoutObject, AXObjectCacheImpl* axObjectCache)
+AXARIAGridRow::AXARIAGridRow(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
     : AXTableRow(layoutObject, axObjectCache)
 {
 }
@@ -44,7 +44,7 @@ AXARIAGridRow::~AXARIAGridRow()
 {
 }
 
-PassRefPtr<AXARIAGridRow> AXARIAGridRow::create(LayoutObject* layoutObject, AXObjectCacheImpl* axObjectCache)
+PassRefPtr<AXARIAGridRow> AXARIAGridRow::create(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
 {
     return adoptRef(new AXARIAGridRow(layoutObject, axObjectCache));
 }