Maintain HostZoom connection per-frame on browser side

content/browser/host_zoom_map_observer.h

Index: content/browser/host_zoom_map_observer.h
diff --git a/content/browser/host_zoom_map_observer.h b/content/browser/host_zoom_map_observer.h
index 4d0e730b86afbb398664ee5d2f3a5327716bf163..b61bad0b5f02af22ed02c6d0ac119c73dba09fae 100644
--- a/content/browser/host_zoom_map_observer.h
+++ b/content/browser/host_zoom_map_observer.h
@@ -21,8 +21,9 @@ class HostZoomMapObserver : private WebContentsObserver {
   // WebContentsObserver implementation:
   void ReadyToCommitNavigation(NavigationHandle* navigation_handle) override;
   void RenderFrameCreated(RenderFrameHost* rfh) override;
+  void RenderFrameDeleted(RenderFrameHost* rfh) override;
 
-  mojom::HostZoomAssociatedPtr host_zoom_;
+  std::map<RenderFrameHost*, mojom::HostZoomAssociatedPtr> host_zoom_ptrs_;
 };
 
 }  // namespace content