Initialize test configuration to a default value.

content/shell/renderer/layout_test/blink_test_runner.cc

 // Copyright (c) 2012 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/blink_test_runner.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <clocale>
@@ skipping 234 matching lines @@
           .Append(FILE_PATH_LITERAL("LayoutTests/"))
           .AppendASCII(path);
   return WebURL(net::FilePathToFileURL(new_path));
 }
 
 }  // namespace
 
 BlinkTestRunner::BlinkTestRunner(RenderView* render_view)
     : RenderViewObserver(render_view),
       RenderViewObserverTracker<BlinkTestRunner>(render_view),
+      test_config_(mojom::ShellTestConfiguration::New()),
       is_main_window_(false),
       focus_on_next_commit_(false),
       leak_detector_(new LeakDetector(this)) {
+  test_config_->enable_pixel_dumping = true;

[Sam McNally, 2017/05/10 07:55:44]

Why does this default to true?

[Jia, 2017/05/10 22:55:29]

Because the old struct ShellTestConfiguration default initializes this field to
true. Please see https://codereview.chromium.org/2594913002
shell_test_configuration.cc

[Sam McNally, 2017/05/10 23:37:13]

In that case, maybe it makes sense to set that as the default in the mojom. See
https://chromium.googlesource.com/chromium/src/+/master/mojo/public/tools/bin....

[Jia, 2017/05/11 00:42:02]

Done. Thanks for pointing out!

 }
 
 BlinkTestRunner::~BlinkTestRunner() {
 }
 
 // WebTestDelegate  -----------------------------------------------------------
 
 void BlinkTestRunner::ClearEditCommand() {
   render_view()->ClearEditCommands();
 }
@@ skipping 791 matching lines @@
 void BlinkTestRunner::ReportLeakDetectionResult(
     const LeakDetectionResult& report) {
   Send(new ShellViewHostMsg_LeakDetectionDone(routing_id(), report));
 }
 
 void BlinkTestRunner::OnDestruct() {
   delete this;
 }
 
 }  // namespace content