[Autofill] Give the PasswordAutofillAgent first shot at handling mouse events.

components/autofill/renderer/password_autofill_agent.h

Index: components/autofill/renderer/password_autofill_agent.h
diff --git a/components/autofill/renderer/password_autofill_agent.h b/components/autofill/renderer/password_autofill_agent.h
index 1edb5814fc7ba2300929a2464a59d6f81abdc1c3..e2955fd929bb6ab8b26b53fadcb9ddaa57bf6478 100644
--- a/components/autofill/renderer/password_autofill_agent.h
+++ b/components/autofill/renderer/password_autofill_agent.h
@@ -49,6 +49,9 @@ class PasswordAutofillAgent : public content::RenderViewObserver,
   // cleared when the selection changes.  However, this method returns
   // true when |node| is fillable by password Autofill.
   bool DidClearAutofillSelection(const WebKit::WebNode& node);
+  // Shows an Autofill popup with username suggestions for |element|.
+  // Returns true if any suggestions were shown, false otherwise.
+  bool ShowSuggestions(const WebKit::WebInputElement& element);
 
  private:
   friend class PasswordAutofillAgentTest;