Send wheel gestures from event sender.

content/shell/renderer/layout_test/layout_test_render_process_observer.cc

Index: content/shell/renderer/layout_test/layout_test_render_process_observer.cc
diff --git a/content/shell/renderer/layout_test/layout_test_render_process_observer.cc b/content/shell/renderer/layout_test/layout_test_render_process_observer.cc
index 02f1815125cf81e14a7db29fe0fc56fcd084e0ce..d62ae5838cfeeacd1d09904fc55085997255e65a 100644
--- a/content/shell/renderer/layout_test/layout_test_render_process_observer.cc
+++ b/content/shell/renderer/layout_test/layout_test_render_process_observer.cc
@@ -5,7 +5,10 @@
 #include "content/shell/renderer/layout_test/layout_test_render_process_observer.h"
 
 #include "base/command_line.h"
+#include "components/test_runner/event_sender.h"
+#include "components/test_runner/test_interfaces.h"
 #include "components/test_runner/web_test_interfaces.h"
+#include "content/common/input/input_event_utils.h"
 #include "content/public/common/content_client.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
@@ -71,6 +74,7 @@ void LayoutTestRenderProcessObserver::WebKitInitialized() {
 
   test_interfaces_.reset(new test_runner::WebTestInterfaces);
   test_interfaces_->ResetAll();
+  test_interfaces_->SetSendWheelGestures(UseGestureBasedWheelScrolling());
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableFontAntialiasing)) {
     blink::setFontAntialiasingEnabledForTest(true);