Destroy WebWidgetTestClient when its WebWidget is destroyed.

content/shell/renderer/layout_test/layout_test_render_frame_observer.cc

 // Copyright 2013 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.
 
 #include "content/shell/renderer/layout_test/layout_test_render_frame_observer.h"
 
 #include <string>
 
 #include "components/test_runner/web_test_interfaces.h"
+#include "components/test_runner/web_test_proxy.h"
 #include "components/test_runner/web_test_runner.h"
 #include "content/public/renderer/render_frame.h"
+#include "content/public/test/layouttest_support.h"
 #include "content/shell/common/shell_messages.h"
 #include "content/shell/renderer/layout_test/blink_test_runner.h"
 #include "content/shell/renderer/layout_test/layout_test_render_thread_observer.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 
 namespace content {
 
 LayoutTestRenderFrameObserver::LayoutTestRenderFrameObserver(
     RenderFrame* render_frame)
@@ skipping 15 matching lines @@
     IPC_MESSAGE_HANDLER(ShellViewMsg_SetTestConfiguration,
                         OnSetTestConfiguration)
     IPC_MESSAGE_HANDLER(ShellViewMsg_SetupSecondaryRenderer,
                         OnSetupSecondaryRenderer)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
+void LayoutTestRenderFrameObserver::FrameDetached() {
+  if (render_frame()->IsMainFrame()) {
+    test_runner::WebTestProxyBase* proxy =
+        GetWebTestProxyBase(render_frame()->GetRenderView());
+    proxy->set_web_widget(nullptr);
+    proxy->set_widget_test_client(nullptr);
+  }
+}
+
 void LayoutTestRenderFrameObserver::OnLayoutDumpRequest() {
   std::string dump =
       LayoutTestRenderThreadObserver::GetInstance()
           ->test_interfaces()
           ->TestRunner()
           ->DumpLayout(render_frame()->GetWebFrame());
   Send(new ShellViewHostMsg_LayoutDumpResponse(routing_id(), dump));
 }
 
 void LayoutTestRenderFrameObserver::OnReplicateTestConfiguration(
     const ShellTestConfiguration& test_config) {
   BlinkTestRunner::Get(render_frame()->GetRenderView())
       ->OnReplicateTestConfiguration(test_config);
 }
 
 void LayoutTestRenderFrameObserver::OnSetTestConfiguration(
     const ShellTestConfiguration& test_config) {
   BlinkTestRunner::Get(render_frame()->GetRenderView())
       ->OnSetTestConfiguration(test_config);
 }
 
 void LayoutTestRenderFrameObserver::OnSetupSecondaryRenderer() {
   BlinkTestRunner::Get(render_frame()->GetRenderView())
       ->OnSetupSecondaryRenderer();
 }
 
 }  // namespace content