[DevTools] Use InspectorFrontendHost.readyForTest for layout tests.

content/shell/browser/layout_test/layout_test_devtools_frontend.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 CONTENT_SHELL_BROWSER_LAYOUT_TEST_LAYOUT_TEST_DEVTOOLS_FRONTEND_H_
 #define CONTENT_SHELL_BROWSER_LAYOUT_TEST_LAYOUT_TEST_DEVTOOLS_FRONTEND_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "content/shell/browser/shell_devtools_frontend.h"
 
 namespace content {
 
 class RenderViewHost;
 class Shell;
 class WebContents;
 
 class LayoutTestDevToolsFrontend : public ShellDevToolsFrontend {
  public:
   static LayoutTestDevToolsFrontend* Show(WebContents* inspected_contents,
                                           const std::string& settings,
                                           const std::string& frontend_url);
 
   static GURL GetDevToolsPathAsURL(const std::string& settings,
                                    const std::string& frontend_url);
 
   void ReuseFrontend(const std::string& settings,
                      const std::string frontend_url);
+  void EvaluateInFrontend(int call_id, const std::string& expression);
 
  private:
   LayoutTestDevToolsFrontend(Shell* frontend_shell,
                              WebContents* inspected_contents);
   ~LayoutTestDevToolsFrontend() override;
 
   // content::DevToolsAgentHostClient implementation.
   void AgentHostClosed(DevToolsAgentHost* agent_host, bool replaced) override;
 
+  // ShellDevToolsFrontend overrides.
+  void HandleMessageFromDevToolsFrontend(const std::string& message) override;
+
   // WebContentsObserver implementation.
   void RenderProcessGone(base::TerminationStatus status) override;
 
+  bool ready_for_test_;
+  std::vector<std::pair<int, std::string>> pending_evaluations_;
+
   DISALLOW_COPY_AND_ASSIGN(LayoutTestDevToolsFrontend);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_BROWSER_LAYOUT_TEST_LAYOUT_TEST_DEVTOOLS_FRONTEND_H_