Allow multiple logging::LogMessage{Handler,Listener}s

chrome/test/base/web_ui_browser_test.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_TEST_BASE_WEB_UI_BROWSER_TEST_H_
 #define CHROME_TEST_BASE_WEB_UI_BROWSER_TEST_H_
 
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/javascript_browser_test.h"
 
 namespace base {
 class Value;
 }
 
 namespace content {
 class RenderViewHost;
 class WebUI;
 class WebUIMessageHandler;
 }
 
 class TestChromeWebUIControllerFactory;
 class WebUITestHandler;
 
+class WebUILogMessageListener : logging::LogMessageListener {
+ public:
+  void OnMessage(int severity,
+                 const char* file,
+                 int line,
+                 size_t message_start,
+                 const std::string& str) override;
+};
+
 // The runner of WebUI javascript based tests.
 // See chrome/test/data/webui/test_api.js for the javascript side test API's.
 //
 // These tests should follow the form given in:
 // chrome/test/data/webui/sample_downloads.js.
 // and the lone test within this class.
 class WebUIBrowserTest : public JavaScriptBrowserTest {
  public:
   ~WebUIBrowserTest() override;
 
@@ skipping 108 matching lines @@
   // Saves the states of |test_fixture| and |test_name| for calling
   // PreloadJavascriptLibraries().
   std::string preload_test_fixture_;
   std::string preload_test_name_;
 
   // When this is non-NULL, this is The WebUI instance used for testing.
   // Otherwise the selected tab's web_ui is used.
   content::WebUI* override_selected_web_ui_;
 
   std::unique_ptr<TestChromeWebUIControllerFactory> test_factory_;
+
+  WebUILogMessageListener log_listener_;
 };
 
 #endif  // CHROME_TEST_BASE_WEB_UI_BROWSER_TEST_H_