Implement AutomationNode.querySelector().

chrome/browser/extensions/api/automation_internal/automation_internal_api.h

Index: chrome/browser/extensions/api/automation_internal/automation_internal_api.h
diff --git a/chrome/browser/extensions/api/automation_internal/automation_internal_api.h b/chrome/browser/extensions/api/automation_internal/automation_internal_api.h
index 7912419461709a652dc48f9fb078a10d941fb6d3..a5a8b7e42d2d8d7153f2d37ef6bcacd96ffe2d3a 100644
--- a/chrome/browser/extensions/api/automation_internal/automation_internal_api.h
+++ b/chrome/browser/extensions/api/automation_internal/automation_internal_api.h
@@ -68,6 +68,28 @@ class AutomationInternalEnableDesktopFunction
   ResponseAction Run() override;
 };
 
+class AutomationInternalQuerySelectorFunction
+    : public UIThreadExtensionFunction {
+  DECLARE_EXTENSION_FUNCTION("automationInternal.querySelector",
+                             AUTOMATIONINTERNAL_ENABLEDESKTOP)
+
+ public:
+  typedef base::Callback<void(const std::string& error,
+                              int result_acc_obj_id)> Callback;
+
+ protected:
+  ~AutomationInternalQuerySelectorFunction() override {}
+
+  ResponseAction Run() override;
+
+ private:
+  void OnResponse(const std::string& error, int result_acc_obj_id);
+
+  // Used for assigning a unique ID to each request so that the response can be
+  // routed appropriately.
+  static int query_request_id_counter_;
+};
+
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_AUTOMATION_INTERNAL_AUTOMATION_INTERNAL_API_H_