Implementing answer card hover highlight.

ui/app_list/search_result_observer.h

Index: ui/app_list/search_result_observer.h
diff --git a/ui/app_list/search_result_observer.h b/ui/app_list/search_result_observer.h
index 72ed4fb25d56c0fc4276b713e8cd9d32f0a539ff..3987e88736d1c4c6b255b615b5bf781ab035c10e 100644
--- a/ui/app_list/search_result_observer.h
+++ b/ui/app_list/search_result_observer.h
@@ -32,6 +32,13 @@ class APP_LIST_EXPORT SearchResultObserver {
   // Invoked just before the SearchResult is destroyed.
   virtual void OnResultDestroying() {}
 
+  // Invoked when SearchResult has an associated view, and the mouse cursor
+  // enters or exits that view. This is needed because the view is
+  // views::WebView and existing views mouse enter/exit events that are sent to
+  // its parent indicate the mouse "exited" the parent when it's actually over
+  // the WebView child.
+  virtual void OnViewHoverStateChanged() {}
+
  protected:
   virtual ~SearchResultObserver() {}
 };