aura: Fix a couple of bug (really the same bug at two different places) for drag

content/browser/web_contents/web_contents_view_aura.h

Index: content/browser/web_contents/web_contents_view_aura.h
diff --git a/content/browser/web_contents/web_contents_view_aura.h b/content/browser/web_contents/web_contents_view_aura.h
index 94c29164c87878ddbabfc8503e016384117b5cfa..44af860810fedccae921ba2ff2677cf4fb5b2049 100644
--- a/content/browser/web_contents/web_contents_view_aura.h
+++ b/content/browser/web_contents/web_contents_view_aura.h
@@ -138,6 +138,12 @@ class CONTENT_EXPORT WebContentsViewAura
 
   content::WebDragDestDelegate* drag_dest_delegate_;
 
+  // We keep track of the render view host we're dragging over.  If it changes
+  // during a drag, we need to re-send the DragEnter message.  WARNING:
+  // this pointer should never be dereferenced.  We only use it for comparing
+  // pointers.
+  void* current_rvh_for_drag_;
+
   DISALLOW_COPY_AND_ASSIGN(WebContentsViewAura);
 };