Add test_runner hook to dump drag image.

content/shell/renderer/test_runner/test_runner.cc

Index: content/shell/renderer/test_runner/test_runner.cc
diff --git a/content/shell/renderer/test_runner/test_runner.cc b/content/shell/renderer/test_runner/test_runner.cc
index 7bf164bbfbb5dbf71db4a03aa041a4f82b4e3cc7..2b79535bcefc506a7094f634a0ebe439c13a6f1f 100644
--- a/content/shell/renderer/test_runner/test_runner.cc
+++ b/content/shell/renderer/test_runner/test_runner.cc
@@ -255,6 +255,7 @@ class TestRunnerBindings : public gin::Wrappable<TestRunnerBindings> {
   void DumpResourceRequestPriorities();
   void SetUseMockTheme(bool use);
   void WaitUntilExternalURLLoad();
+  void DumpDragImage();
   void ShowWebInspector(gin::Arguments* args);
   void CloseWebInspector();
   bool IsChooserShown();
@@ -493,6 +494,7 @@ gin::ObjectTemplateBuilder TestRunnerBindings::GetObjectTemplateBuilder(
       .SetMethod("setUseMockTheme", &TestRunnerBindings::SetUseMockTheme)
       .SetMethod("waitUntilExternalURLLoad",
                  &TestRunnerBindings::WaitUntilExternalURLLoad)
+      .SetMethod("dumpDragImage", &TestRunnerBindings::DumpDragImage)
       .SetMethod("showWebInspector", &TestRunnerBindings::ShowWebInspector)
       .SetMethod("closeWebInspector", &TestRunnerBindings::CloseWebInspector)
       .SetMethod("isChooserShown", &TestRunnerBindings::IsChooserShown)
@@ -1225,6 +1227,11 @@ void TestRunnerBindings::WaitUntilExternalURLLoad() {
     runner_->WaitUntilExternalURLLoad();
 }
 
+void TestRunnerBindings::DumpDragImage() {
+  if (runner_)
+    runner_->DumpDragImage();
+}
+
 void TestRunnerBindings::ShowWebInspector(gin::Arguments* args) {
   if (runner_) {
     std::string settings;
@@ -1659,6 +1666,7 @@ void TestRunner::Reset() {
   dump_spell_check_callbacks_ = false;
   dump_back_forward_list_ = false;
   dump_selection_rect_ = false;
+  dump_drag_image_ = false;
   test_repaint_ = false;
   sweep_horizontally_ = false;
   is_printing_ = false;
@@ -1929,6 +1937,10 @@ void TestRunner::setToolTipText(const WebString& text) {
   tooltip_text_ = text.utf8();
 }
 
+bool TestRunner::shouldDumpDragImage() {
+  return dump_drag_image_;
+}
+
 bool TestRunner::midiAccessorResult() {
   return midi_accessor_result_;
 }
@@ -2725,6 +2737,11 @@ void TestRunner::WaitUntilExternalURLLoad() {
   wait_until_external_url_load_ = true;
 }
 
+void TestRunner::DumpDragImage() {
+  DumpAsTextWithPixelResults();
+  dump_drag_image_ = true;
+}
+
 void TestRunner::CloseWebInspector() {
   delegate_->CloseDevTools();
 }