Fix crash when destroying a RenderWidgetHost that holds the pointer

content/browser/frame_host/render_widget_host_view_guest_unittest.cc

 // 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.
 
 #include "content/browser/frame_host/render_widget_host_view_guest.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/macros.h"
@@ skipping 24 matching lines @@
  public:
   MockRenderWidgetHostDelegate() {}
   ~MockRenderWidgetHostDelegate() override {}
 
  private:
   // RenderWidgetHostDelegate:
   void Cut() override {}
   void Copy() override {}
   void Paste() override {}
   void SelectAll() override {}
+  bool HasMouseLock(RenderWidgetHostImpl*) override { return false; }
 };
 
 class RenderWidgetHostViewGuestTest : public testing::Test {
  public:
   RenderWidgetHostViewGuestTest() {}
 
   void SetUp() override {
 #if !defined(OS_ANDROID)
     ImageTransportFactory::InitializeForUnitTests(
         std::unique_ptr<ImageTransportFactory>(
@@ skipping 227 matching lines @@
 
   browser_plugin_guest_->set_attached(false);
   browser_plugin_guest_->ResetTestData();
 
   view_->OnSwapCompositorFrame(
       0, CreateDelegatedFrame(scale_factor, view_size, view_rect));
   EXPECT_TRUE(surface_id().is_null());
 }
 
 }  // namespace content